sqlparser_common.rs

// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#![warn(clippy::all)]
//! Test SQL syntax, which all sqlparser dialects must parse in the same way.
//!
//! Note that it does not mean all SQL here is valid in all the dialects, only
//! that 1) it's either standard or widely supported and 2) it can be parsed by
//! sqlparser regardless of the chosen dialect (i.e. it doesn't conflict with
//! dialect-specific parsing rules).

use matches::assert_matches;

use sqlparser::ast::*;
use sqlparser::parser::*;
use sqlparser::test_utils::{all_dialects, expr_from_projection, number, only};

#[test]
fn parse_insert_values() {
    let row = vec![
        Expr::Value(number("1")),
        Expr::Value(number("2")),
        Expr::Value(number("3")),
    ];
    let rows1 = vec![row.clone()];
    let rows2 = vec![row.clone(), row];

    let sql = "INSERT INTO customer VALUES (1, 2, 3)";
    check_one(sql, "customer", &[], &rows1);

    let sql = "INSERT INTO customer VALUES (1, 2, 3), (1, 2, 3)";
    check_one(sql, "customer", &[], &rows2);

    let sql = "INSERT INTO public.customer VALUES (1, 2, 3)";
    check_one(sql, "public.customer", &[], &rows1);

    let sql = "INSERT INTO db.public.customer VALUES (1, 2, 3)";
    check_one(sql, "db.public.customer", &[], &rows1);

    let sql = "INSERT INTO public.customer (id, name, active) VALUES (1, 2, 3)";
    check_one(
        sql,
        "public.customer",
        &["id".to_string(), "name".to_string(), "active".to_string()],
        &rows1,
    );

    fn check_one(
        sql: &str,
        expected_table_name: &str,
        expected_columns: &[String],
        expected_rows: &[Vec<Expr>],
    ) {
        match verified_stmt(sql) {
            Statement::Insert {
                table_name,
                columns,
                source,
                ..
            } => {
                assert_eq!(table_name.to_string(), expected_table_name);
                assert_eq!(columns.len(), expected_columns.len());
                for (index, column) in columns.iter().enumerate() {
                    assert_eq!(column, &Ident::new(expected_columns[index].clone()));
                }
                match &source.body {
                    SetExpr::Values(Values(values)) => assert_eq!(values.as_slice(), expected_rows),
                    _ => unreachable!(),
                }
            }
            _ => unreachable!(),
        }
    }

    verified_stmt("INSERT INTO customer WITH foo AS (SELECT 1) SELECT * FROM foo UNION VALUES (1)");
}

#[test]
fn parse_insert_invalid() {
    let sql = "INSERT public.customer (id, name, active) VALUES (1, 2, 3)";
    let res = parse_sql_statements(sql);
    assert_eq!(
        ParserError::ParserError("Expected INTO, found: public".to_string()),
        res.unwrap_err()
    );
}

#[test]
fn parse_update() {
    let sql = "UPDATE t SET a = 1, b = 2, c = 3 WHERE d";
    match verified_stmt(sql) {
        Statement::Update {
            table_name,
            assignments,
            selection,
            ..
        } => {
            assert_eq!(table_name.to_string(), "t".to_string());
            assert_eq!(
                assignments,
                vec![
                    Assignment {
                        id: "a".into(),
                        value: Expr::Value(number("1")),
                    },
                    Assignment {
                        id: "b".into(),
                        value: Expr::Value(number("2")),
                    },
                    Assignment {
                        id: "c".into(),
                        value: Expr::Value(number("3")),
                    },
                ]
            );
            assert_eq!(selection.unwrap(), Expr::Identifier("d".into()));
        }
        _ => unreachable!(),
    }

    verified_stmt("UPDATE t SET a = 1, a = 2, a = 3");

    let sql = "UPDATE t WHERE 1";
    let res = parse_sql_statements(sql);
    assert_eq!(
        ParserError::ParserError("Expected SET, found: WHERE".to_string()),
        res.unwrap_err()
    );

    let sql = "UPDATE t SET a = 1 extrabadstuff";
    let res = parse_sql_statements(sql);
    assert_eq!(
        ParserError::ParserError("Expected end of statement, found: extrabadstuff".to_string()),
        res.unwrap_err()
    );
}

#[test]
fn parse_invalid_table_name() {
    let ast = all_dialects().run_parser_method("db.public..customer", Parser::parse_object_name);
    assert!(ast.is_err());
}

#[test]
fn parse_no_table_name() {
    let ast = all_dialects().run_parser_method("", Parser::parse_object_name);
    assert!(ast.is_err());
}

#[test]
fn parse_delete_statement() {
    let sql = "DELETE FROM \"table\"";
    match verified_stmt(sql) {
        Statement::Delete { table_name, .. } => {
            assert_eq!(
                ObjectName(vec![Ident::with_quote('"', "table")]),
                table_name
            );
        }
        _ => unreachable!(),
    }
}

#[test]
fn parse_where_delete_statement() {
    use self::BinaryOperator::*;

    let sql = "DELETE FROM foo WHERE name = 5";
    match verified_stmt(sql) {
        Statement::Delete {
            table_name,
            selection,
            ..
        } => {
            assert_eq!(ObjectName(vec![Ident::new("foo")]), table_name);

            assert_eq!(
                Expr::BinaryOp {
                    left: Box::new(Expr::Identifier(Ident::new("name"))),
                    op: Eq,
                    right: Box::new(Expr::Value(number("5"))),
                },
                selection.unwrap(),
            );
        }
        _ => unreachable!(),
    }
}

#[test]
fn parse_top_level() {
    verified_stmt("SELECT 1");
    verified_stmt("(SELECT 1)");
    verified_stmt("((SELECT 1))");
    verified_stmt("VALUES (1)");
}

#[test]
fn parse_simple_select() {
    let sql = "SELECT id, fname, lname FROM customer WHERE id = 1 LIMIT 5";
    let select = verified_only_select(sql);
    assert_eq!(false, select.distinct);
    assert_eq!(3, select.projection.len());
    let select = verified_query(sql);
    assert_eq!(Some(Expr::Value(number("5"))), select.limit);
}

#[test]
fn parse_limit_is_not_an_alias() {
    // In dialects supporting LIMIT it shouldn't be parsed as a table alias
    let ast = verified_query("SELECT id FROM customer LIMIT 1");
    assert_eq!(Some(Expr::Value(number("1"))), ast.limit);

    let ast = verified_query("SELECT 1 LIMIT 5");
    assert_eq!(Some(Expr::Value(number("5"))), ast.limit);
}

#[test]
fn parse_select_distinct() {
    let sql = "SELECT DISTINCT name FROM customer";
    let select = verified_only_select(sql);
    assert_eq!(true, select.distinct);
    assert_eq!(
        &SelectItem::UnnamedExpr(Expr::Identifier(Ident::new("name"))),
        only(&select.projection)
    );
}

#[test]
fn parse_select_all() {
    one_statement_parses_to("SELECT ALL name FROM customer", "SELECT name FROM customer");
}

#[test]
fn parse_select_all_distinct() {
    let result = parse_sql_statements("SELECT ALL DISTINCT name FROM customer");
    assert_eq!(
        ParserError::ParserError("Cannot specify both ALL and DISTINCT in SELECT".to_string()),
        result.unwrap_err(),
    );
}

#[test]
fn parse_select_wildcard() {
    let sql = "SELECT * FROM foo";
    let select = verified_only_select(sql);
    assert_eq!(&SelectItem::Wildcard, only(&select.projection));

    let sql = "SELECT foo.* FROM foo";
    let select = verified_only_select(sql);
    assert_eq!(
        &SelectItem::QualifiedWildcard(ObjectName(vec![Ident::new("foo")])),
        only(&select.projection)
    );

    let sql = "SELECT myschema.mytable.* FROM myschema.mytable";
    let select = verified_only_select(sql);
    assert_eq!(
        &SelectItem::QualifiedWildcard(ObjectName(vec![
            Ident::new("myschema"),
            Ident::new("mytable"),
        ])),
        only(&select.projection)
    );
}

#[test]
fn parse_count_wildcard() {
    verified_only_select(
        "SELECT COUNT(Employee.*) FROM Order JOIN Employee ON Order.employee = Employee.id",
    );
}

#[test]
fn parse_column_aliases() {
    let sql = "SELECT a.col + 1 AS newname FROM foo AS a";
    let select = verified_only_select(sql);
    if let SelectItem::ExprWithAlias {
        expr: Expr::BinaryOp {
            ref op, ref right, ..
        },
        ref alias,
    } = only(&select.projection)
    {
        assert_eq!(&BinaryOperator::Plus, op);
        assert_eq!(&Expr::Value(number("1")), right.as_ref());
        assert_eq!(&Ident::new("newname"), alias);
    } else {
        panic!("Expected ExprWithAlias")
    }

    // alias without AS is parsed correctly:
    one_statement_parses_to("SELECT a.col + 1 newname FROM foo AS a", &sql);
}

#[test]
fn test_eof_after_as() {
    let res = parse_sql_statements("SELECT foo AS");
    assert_eq!(
        ParserError::ParserError("Expected an identifier after AS, found: EOF".to_string()),
        res.unwrap_err()
    );

    let res = parse_sql_statements("SELECT 1 FROM foo AS");
    assert_eq!(
        ParserError::ParserError("Expected an identifier after AS, found: EOF".to_string()),
        res.unwrap_err()
    );
}

#[test]
fn parse_select_count_wildcard() {
    let sql = "SELECT COUNT(*) FROM customer";
    let select = verified_only_select(sql);
    assert_eq!(
        &Expr::Function(Function {
            name: ObjectName(vec![Ident::new("COUNT")]),
            args: vec![Expr::Wildcard],
            over: None,
            distinct: false,
        }),
        expr_from_projection(only(&select.projection))
    );
}

#[test]
fn parse_select_count_distinct() {
    let sql = "SELECT COUNT(DISTINCT + x) FROM customer";
    let select = verified_only_select(sql);
    assert_eq!(
        &Expr::Function(Function {
            name: ObjectName(vec![Ident::new("COUNT")]),
            args: vec![Expr::UnaryOp {
                op: UnaryOperator::Plus,
                expr: Box::new(Expr::Identifier(Ident::new("x")))
            }],
            over: None,
            distinct: true,
        }),
        expr_from_projection(only(&select.projection))
    );

    one_statement_parses_to(
        "SELECT COUNT(ALL + x) FROM customer",
        "SELECT COUNT(+ x) FROM customer",
    );

    let sql = "SELECT COUNT(ALL DISTINCT + x) FROM customer";
    let res = parse_sql_statements(sql);
    assert_eq!(
        ParserError::ParserError(
            "Cannot specify both ALL and DISTINCT in function: COUNT".to_string()
        ),
        res.unwrap_err()
    );
}

#[test]
fn parse_not() {
    let sql = "SELECT id FROM customer WHERE NOT salary = ''";
    let _ast = verified_only_select(sql);
    //TODO: add assertions
}

#[test]
fn parse_invalid_infix_not() {
    let res = parse_sql_statements("SELECT c FROM t WHERE c NOT (");
    assert_eq!(
        ParserError::ParserError("Expected end of statement, found: NOT".to_string()),
        res.unwrap_err(),
    );
}

#[test]
fn parse_collate() {
    let sql = "SELECT name COLLATE \"de_DE\" FROM customer";
    assert_matches!(
        only(&all_dialects().verified_only_select(sql).projection),
        SelectItem::UnnamedExpr(Expr::Collate { .. })
    );
}

#[test]
fn parse_select_string_predicate() {
    let sql = "SELECT id, fname, lname FROM customer \
               WHERE salary <> 'Not Provided' AND salary <> ''";
    let _ast = verified_only_select(sql);
    //TODO: add assertions
}

#[test]
fn parse_projection_nested_type() {
    let sql = "SELECT customer.address.state FROM foo";
    let _ast = verified_only_select(sql);
    //TODO: add assertions
}

#[test]
fn parse_null_in_select() {
    let sql = "SELECT NULL";
    let select = verified_only_select(sql);
    assert_eq!(
        &Expr::Value(Value::Null),
        expr_from_projection(only(&select.projection)),
    );
}

#[test]
fn parse_escaped_single_quote_string_predicate() {
    use self::BinaryOperator::*;
    let sql = "SELECT id, fname, lname FROM customer \
               WHERE salary <> 'Jim''s salary'";
    let ast = verified_only_select(sql);
    assert_eq!(
        Some(Expr::BinaryOp {
            left: Box::new(Expr::Identifier(Ident::new("salary"))),
            op: NotEq,
            right: Box::new(Expr::Value(Value::SingleQuotedString(
                "Jim's salary".to_string()
            )))
        }),
        ast.selection,
    );
}

#[test]
fn parse_number() {
    let expr = verified_expr("1.0");

    #[cfg(feature = "bigdecimal")]
    assert_eq!(
        expr,
        Expr::Value(Value::Number(bigdecimal::BigDecimal::from(1)))
    );

    #[cfg(not(feature = "bigdecimal"))]
    assert_eq!(expr, Expr::Value(Value::Number("1.0".into())));
}

#[test]
fn parse_compound_expr_1() {
    use self::BinaryOperator::*;
    use self::Expr::*;
    let sql = "a + b * c";
    assert_eq!(
        BinaryOp {
            left: Box::new(Identifier(Ident::new("a"))),
            op: Plus,
            right: Box::new(BinaryOp {
                left: Box::new(Identifier(Ident::new("b"))),
                op: Multiply,
                right: Box::new(Identifier(Ident::new("c")))
            })
        },
        verified_expr(sql)
    );
}

#[test]
fn parse_compound_expr_2() {
    use self::BinaryOperator::*;
    use self::Expr::*;
    let sql = "a * b + c";
    assert_eq!(
        BinaryOp {
            left: Box::new(BinaryOp {
                left: Box::new(Identifier(Ident::new("a"))),
                op: Multiply,
                right: Box::new(Identifier(Ident::new("b")))
            }),
            op: Plus,
            right: Box::new(Identifier(Ident::new("c")))
        },
        verified_expr(sql)
    );
}

#[test]
fn parse_unary_math() {
    use self::Expr::*;
    let sql = "- a + - b";
    assert_eq!(
        BinaryOp {
            left: Box::new(UnaryOp {
                op: UnaryOperator::Minus,
                expr: Box::new(Identifier(Ident::new("a"))),
            }),
            op: BinaryOperator::Plus,
            right: Box::new(UnaryOp {
                op: UnaryOperator::Minus,
                expr: Box::new(Identifier(Ident::new("b"))),
            }),
        },
        verified_expr(sql)
    );
}

#[test]
fn parse_is_null() {
    use self::Expr::*;
    let sql = "a IS NULL";
    assert_eq!(
        IsNull(Box::new(Identifier(Ident::new("a")))),
        verified_expr(sql)
    );
}

#[test]
fn parse_is_not_null() {
    use self::Expr::*;
    let sql = "a IS NOT NULL";
    assert_eq!(
        IsNotNull(Box::new(Identifier(Ident::new("a")))),
        verified_expr(sql)
    );
}

#[test]
fn parse_not_precedence() {
    // NOT has higher precedence than OR/AND, so the following must parse as (NOT true) OR true
    let sql = "NOT true OR true";
    assert_matches!(verified_expr(sql), Expr::BinaryOp {
        op: BinaryOperator::Or,
        ..
    });

    // But NOT has lower precedence than comparison operators, so the following parses as NOT (a IS NULL)
    let sql = "NOT a IS NULL";
    assert_matches!(verified_expr(sql), Expr::UnaryOp {
        op: UnaryOperator::Not,
        ..
    });

    // NOT has lower precedence than BETWEEN, so the following parses as NOT (1 NOT BETWEEN 1 AND 2)
    let sql = "NOT 1 NOT BETWEEN 1 AND 2";
    assert_eq!(
        verified_expr(sql),
        Expr::UnaryOp {
            op: UnaryOperator::Not,
            expr: Box::new(Expr::Between {
                expr: Box::new(Expr::Value(number("1"))),
                low: Box::new(Expr::Value(number("1"))),
                high: Box::new(Expr::Value(number("2"))),
                negated: true,
            }),
        },
    );

    // NOT has lower precedence than LIKE, so the following parses as NOT ('a' NOT LIKE 'b')
    let sql = "NOT 'a' NOT LIKE 'b'";
    assert_eq!(
        verified_expr(sql),
        Expr::UnaryOp {
            op: UnaryOperator::Not,
            expr: Box::new(Expr::BinaryOp {
                left: Box::new(Expr::Value(Value::SingleQuotedString("a".into()))),
                op: BinaryOperator::NotLike,
                right: Box::new(Expr::Value(Value::SingleQuotedString("b".into()))),
            }),
        },
    );

    // NOT has lower precedence than IN, so the following parses as NOT (a NOT IN 'a')
    let sql = "NOT a NOT IN ('a')";
    assert_eq!(
        verified_expr(sql),
        Expr::UnaryOp {
            op: UnaryOperator::Not,
            expr: Box::new(Expr::InList {
                expr: Box::new(Expr::Identifier("a".into())),
                list: vec![Expr::Value(Value::SingleQuotedString("a".into()))],
                negated: true,
            }),
        },
    );
}

#[test]
fn parse_like() {
    fn chk(negated: bool) {
        let sql = &format!(
            "SELECT * FROM customers WHERE name {}LIKE '%a'",
            if negated { "NOT " } else { "" }
        );
        let select = verified_only_select(sql);
        assert_eq!(
            Expr::BinaryOp {
                left: Box::new(Expr::Identifier(Ident::new("name"))),
                op: if negated {
                    BinaryOperator::NotLike
                } else {
                    BinaryOperator::Like
                },
                right: Box::new(Expr::Value(Value::SingleQuotedString("%a".to_string()))),
            },
            select.selection.unwrap()
        );

        // This statement tests that LIKE and NOT LIKE have the same precedence.
        // This was previously mishandled (#81).
        let sql = &format!(
            "SELECT * FROM customers WHERE name {}LIKE '%a' IS NULL",
            if negated { "NOT " } else { "" }
        );
        let select = verified_only_select(sql);
        assert_eq!(
            Expr::IsNull(Box::new(Expr::BinaryOp {
                left: Box::new(Expr::Identifier(Ident::new("name"))),
                op: if negated {
                    BinaryOperator::NotLike
                } else {
                    BinaryOperator::Like
                },
                right: Box::new(Expr::Value(Value::SingleQuotedString("%a".to_string()))),
            })),
            select.selection.unwrap()
        );
    }
    chk(false);
    chk(true);
}

#[test]
fn parse_in_list() {
    fn chk(negated: bool) {
        let sql = &format!(
            "SELECT * FROM customers WHERE segment {}IN ('HIGH', 'MED')",
            if negated { "NOT " } else { "" }
        );
        let select = verified_only_select(sql);
        assert_eq!(
            Expr::InList {
                expr: Box::new(Expr::Identifier(Ident::new("segment"))),
                list: vec![
                    Expr::Value(Value::SingleQuotedString("HIGH".to_string())),
                    Expr::Value(Value::SingleQuotedString("MED".to_string())),
                ],
                negated,
            },
            select.selection.unwrap()
        );
    }
    chk(false);
    chk(true);
}

#[test]
fn parse_in_subquery() {
    let sql = "SELECT * FROM customers WHERE segment IN (SELECT segm FROM bar)";
    let select = verified_only_select(sql);
    assert_eq!(
        Expr::InSubquery {
            expr: Box::new(Expr::Identifier(Ident::new("segment"))),
            subquery: Box::new(verified_query("SELECT segm FROM bar")),
            negated: false,
        },
        select.selection.unwrap()
    );
}

#[test]
fn parse_between() {
    fn chk(negated: bool) {
        let sql = &format!(
            "SELECT * FROM customers WHERE age {}BETWEEN 25 AND 32",
            if negated { "NOT " } else { "" }
        );
        let select = verified_only_select(sql);
        assert_eq!(
            Expr::Between {
                expr: Box::new(Expr::Identifier(Ident::new("age"))),
                low: Box::new(Expr::Value(number("25"))),
                high: Box::new(Expr::Value(number("32"))),
                negated,
            },
            select.selection.unwrap()
        );
    }
    chk(false);
    chk(true);
}

#[test]
fn parse_between_with_expr() {
    use self::BinaryOperator::*;
    let sql = "SELECT * FROM t WHERE 1 BETWEEN 1 + 2 AND 3 + 4 IS NULL";
    let select = verified_only_select(sql);
    assert_eq!(
        Expr::IsNull(Box::new(Expr::Between {
            expr: Box::new(Expr::Value(number("1"))),
            low: Box::new(Expr::BinaryOp {
                left: Box::new(Expr::Value(number("1"))),
                op: Plus,
                right: Box::new(Expr::Value(number("2"))),
            }),
            high: Box::new(Expr::BinaryOp {
                left: Box::new(Expr::Value(number("3"))),
                op: Plus,
                right: Box::new(Expr::Value(number("4"))),
            }),
            negated: false,
        })),
        select.selection.unwrap()
    );

    let sql = "SELECT * FROM t WHERE 1 = 1 AND 1 + x BETWEEN 1 AND 2";
    let select = verified_only_select(sql);
    assert_eq!(
        Expr::BinaryOp {
            left: Box::new(Expr::BinaryOp {
                left: Box::new(Expr::Value(number("1"))),
                op: BinaryOperator::Eq,
                right: Box::new(Expr::Value(number("1"))),
            }),
            op: BinaryOperator::And,
            right: Box::new(Expr::Between {
                expr: Box::new(Expr::BinaryOp {
                    left: Box::new(Expr::Value(number("1"))),
                    op: BinaryOperator::Plus,
                    right: Box::new(Expr::Identifier(Ident::new("x"))),
                }),
                low: Box::new(Expr::Value(number("1"))),
                high: Box::new(Expr::Value(number("2"))),
                negated: false,
            }),
        },
        select.selection.unwrap(),
    )
}

#[test]
fn parse_select_order_by() {
    fn chk(sql: &str) {
        let select = verified_query(sql);
        assert_eq!(
            vec![
                OrderByExpr {
                    expr: Expr::Identifier(Ident::new("lname")),
                    asc: Some(true),
                },
                OrderByExpr {
                    expr: Expr::Identifier(Ident::new("fname")),
                    asc: Some(false),
                },
                OrderByExpr {
                    expr: Expr::Identifier(Ident::new("id")),
                    asc: None,
                },
            ],
            select.order_by
        );
    }
    chk("SELECT id, fname, lname FROM customer WHERE id < 5 ORDER BY lname ASC, fname DESC, id");
    // make sure ORDER is not treated as an alias
    chk("SELECT id, fname, lname FROM customer ORDER BY lname ASC, fname DESC, id");
    chk("SELECT 1 AS lname, 2 AS fname, 3 AS id, 4 ORDER BY lname ASC, fname DESC, id");
}

#[test]
fn parse_select_order_by_limit() {
    let sql = "SELECT id, fname, lname FROM customer WHERE id < 5 \
               ORDER BY lname ASC, fname DESC LIMIT 2";
    let select = verified_query(sql);
    assert_eq!(
        vec![
            OrderByExpr {
                expr: Expr::Identifier(Ident::new("lname")),
                asc: Some(true),
            },
            OrderByExpr {
                expr: Expr::Identifier(Ident::new("fname")),
                asc: Some(false),
            },
        ],
        select.order_by
    );
    assert_eq!(Some(Expr::Value(number("2"))), select.limit);
}

#[test]
fn parse_select_group_by() {
    let sql = "SELECT id, fname, lname FROM customer GROUP BY lname, fname";
    let select = verified_only_select(sql);
    assert_eq!(
        vec![
            Expr::Identifier(Ident::new("lname")),
            Expr::Identifier(Ident::new("fname")),
        ],
        select.group_by
    );
}

#[test]
fn parse_select_having() {
    let sql = "SELECT foo FROM bar GROUP BY foo HAVING COUNT(*) > 1";
    let select = verified_only_select(sql);
    assert_eq!(
        Some(Expr::BinaryOp {
            left: Box::new(Expr::Function(Function {
                name: ObjectName(vec![Ident::new("COUNT")]),
                args: vec![Expr::Wildcard],
                over: None,
                distinct: false
            })),
            op: BinaryOperator::Gt,
            right: Box::new(Expr::Value(number("1")))
        }),
        select.having
    );

    let sql = "SELECT 'foo' HAVING 1 = 1";
    let select = verified_only_select(sql);
    assert!(select.having.is_some());
}

#[test]
fn parse_limit_accepts_all() {
    one_statement_parses_to(
        "SELECT id, fname, lname FROM customer WHERE id = 1 LIMIT ALL",
        "SELECT id, fname, lname FROM customer WHERE id = 1",
    );
}

#[test]
fn parse_cast() {
    let sql = "SELECT CAST(id AS bigint) FROM customer";
    let select = verified_only_select(sql);
    assert_eq!(
        &Expr::Cast {
            expr: Box::new(Expr::Identifier(Ident::new("id"))),
            data_type: DataType::BigInt
        },
        expr_from_projection(only(&select.projection))
    );
    one_statement_parses_to(
        "SELECT CAST(id AS BIGINT) FROM customer",
        "SELECT CAST(id AS bigint) FROM customer",
    );

    verified_stmt("SELECT CAST(id AS numeric) FROM customer");

    one_statement_parses_to(
        "SELECT CAST(id AS dec) FROM customer",
        "SELECT CAST(id AS numeric) FROM customer",
    );

    one_statement_parses_to(
        "SELECT CAST(id AS decimal) FROM customer",
        "SELECT CAST(id AS numeric) FROM customer",
    );
}

#[test]
fn parse_extract() {
    let sql = "SELECT EXTRACT(YEAR FROM d)";
    let select = verified_only_select(sql);
    assert_eq!(
        &Expr::Extract {
            field: DateTimeField::Year,
            expr: Box::new(Expr::Identifier(Ident::new("d"))),
        },
        expr_from_projection(only(&select.projection)),
    );

    one_statement_parses_to("SELECT EXTRACT(year from d)", "SELECT EXTRACT(YEAR FROM d)");

    verified_stmt("SELECT EXTRACT(MONTH FROM d)");
    verified_stmt("SELECT EXTRACT(DAY FROM d)");
    verified_stmt("SELECT EXTRACT(HOUR FROM d)");
    verified_stmt("SELECT EXTRACT(MINUTE FROM d)");
    verified_stmt("SELECT EXTRACT(SECOND FROM d)");

    let res = parse_sql_statements("SELECT EXTRACT(MILLISECOND FROM d)");
    assert_eq!(
        ParserError::ParserError("Expected date/time field, found: MILLISECOND".to_string()),
        res.unwrap_err()
    );
}

#[test]
fn parse_create_table() {
    let sql = "CREATE TABLE uk_cities (\
               name VARCHAR(100) NOT NULL,\
               lat DOUBLE NULL,\
               lng DOUBLE,
               constrained INT NULL CONSTRAINT pkey PRIMARY KEY NOT NULL UNIQUE CHECK (constrained > 0),
               ref INT REFERENCES othertable (a, b),\
               ref2 INT references othertable2 on delete cascade on update no action\
               )";
    let ast = one_statement_parses_to(
        sql,
        "CREATE TABLE uk_cities (\
         name character varying(100) NOT NULL, \
         lat double NULL, \
         lng double, \
         constrained int NULL CONSTRAINT pkey PRIMARY KEY NOT NULL UNIQUE CHECK (constrained > 0), \
         ref int REFERENCES othertable (a, b), \
         ref2 int REFERENCES othertable2 ON DELETE CASCADE ON UPDATE NO ACTION)",
    );
    match ast {
        Statement::CreateTable {
            name,
            columns,
            constraints,
            with_options,
            if_not_exists: false,
            external: false,
            file_format: None,
            location: None,
        } => {
            assert_eq!("uk_cities", name.to_string());
            assert_eq!(
                columns,
                vec![
                    ColumnDef {
                        name: "name".into(),
                        data_type: DataType::Varchar(Some(100)),
                        collation: None,
                        options: vec![ColumnOptionDef {
                            name: None,
                            option: ColumnOption::NotNull
                        }],
                    },
                    ColumnDef {
                        name: "lat".into(),
                        data_type: DataType::Double,
                        collation: None,
                        options: vec![ColumnOptionDef {
                            name: None,
                            option: ColumnOption::Null
                        }],
                    },
                    ColumnDef {
                        name: "lng".into(),
                        data_type: DataType::Double,
                        collation: None,
                        options: vec![],
                    },
                    ColumnDef {
                        name: "constrained".into(),
                        data_type: DataType::Int,
                        collation: None,
                        options: vec![
                            ColumnOptionDef {
                                name: None,
                                option: ColumnOption::Null
                            },
                            ColumnOptionDef {
                                name: Some("pkey".into()),
                                option: ColumnOption::Unique { is_primary: true }
                            },
                            ColumnOptionDef {
                                name: None,
                                option: ColumnOption::NotNull
                            },
                            ColumnOptionDef {
                                name: None,
                                option: ColumnOption::Unique { is_primary: false },
                            },
                            ColumnOptionDef {
                                name: None,
                                option: ColumnOption::Check(verified_expr("constrained > 0")),
                            }
                        ],
                    },
                    ColumnDef {
                        name: "ref".into(),
                        data_type: DataType::Int,
                        collation: None,
                        options: vec![ColumnOptionDef {
                            name: None,
                            option: ColumnOption::ForeignKey {
                                foreign_table: ObjectName(vec!["othertable".into()]),
                                referred_columns: vec!["a".into(), "b".into(),],
                                on_delete: None,
                                on_update: None,
                            }
                        }]
                    },
                    ColumnDef {
                        name: "ref2".into(),
                        data_type: DataType::Int,
                        collation: None,
                        options: vec![ColumnOptionDef {
                            name: None,
                            option: ColumnOption::ForeignKey {
                                foreign_table: ObjectName(vec!["othertable2".into()]),
                                referred_columns: vec![],
                                on_delete: Some(ReferentialAction::Cascade),
                                on_update: Some(ReferentialAction::NoAction),
                            }
                        },]
                    }
                ]
            );
            assert!(constraints.is_empty());
            assert_eq!(with_options, vec![]);
        }
        _ => unreachable!(),
    }

    let res = parse_sql_statements("CREATE TABLE t (a int NOT NULL GARBAGE)");
    assert!(res
        .unwrap_err()
        .to_string()
        .contains("Expected column option, found: GARBAGE"));
}

#[test]
fn parse_create_table_with_multiple_on_delete_fails() {
    parse_sql_statements(
        "\
        create table X (\
            y_id int references Y (id) \
            on delete cascade on update cascade on delete no action\
        )",
    )
    .expect_err("should have failed");
}

#[test]
fn parse_create_table_with_on_delete_on_update_2in_any_order() -> Result<(), ParserError> {
    let sql = |options: &str| -> String {
        format!("create table X (y_id int references Y (id) {})", options)
    };

    parse_sql_statements(&sql("on update cascade on delete no action"))?;
    parse_sql_statements(&sql("on delete cascade on update cascade"))?;
    parse_sql_statements(&sql("on update no action"))?;
    parse_sql_statements(&sql("on delete restrict"))?;

    Ok(())
}

#[test]
fn parse_create_table_with_options() {
    let sql = "CREATE TABLE t (c int) WITH (foo = 'bar', a = 123)";
    match verified_stmt(sql) {
        Statement::CreateTable { with_options, .. } => {
            assert_eq!(
                vec![
                    SqlOption {
                        name: "foo".into(),
                        value: Value::SingleQuotedString("bar".into())
                    },
                    SqlOption {
                        name: "a".into(),
                        value: number("123")
                    },
                ],
                with_options
            );
        }
        _ => unreachable!(),
    }
}

#[test]
fn parse_create_table_trailing_comma() {
    let sql = "CREATE TABLE foo (bar int,)";
    all_dialects().one_statement_parses_to(sql, "CREATE TABLE foo (bar int)");
}

#[test]
fn parse_create_external_table() {
    let sql = "CREATE EXTERNAL TABLE uk_cities (\
               name VARCHAR(100) NOT NULL,\
               lat DOUBLE NULL,\
               lng DOUBLE)\
               STORED AS TEXTFILE LOCATION '/tmp/example.csv'";
    let ast = one_statement_parses_to(
        sql,
        "CREATE EXTERNAL TABLE uk_cities (\
         name character varying(100) NOT NULL, \
         lat double NULL, \
         lng double) \
         STORED AS TEXTFILE LOCATION '/tmp/example.csv'",
    );
    match ast {
        Statement::CreateTable {
            name,
            columns,
            constraints,
            with_options,
            if_not_exists,
            external,
            file_format,
            location,
        } => {
            assert_eq!("uk_cities", name.to_string());
            assert_eq!(
                columns,
                vec![
                    ColumnDef {
                        name: "name".into(),
                        data_type: DataType::Varchar(Some(100)),
                        collation: None,
                        options: vec![ColumnOptionDef {
                            name: None,
                            option: ColumnOption::NotNull
                        }],
                    },
                    ColumnDef {
                        name: "lat".into(),
                        data_type: DataType::Double,
                        collation: None,
                        options: vec![ColumnOptionDef {
                            name: None,
                            option: ColumnOption::Null
                        }],
                    },
                    ColumnDef {
                        name: "lng".into(),
                        data_type: DataType::Double,
                        collation: None,
                        options: vec![],
                    },
                ]
            );
            assert!(constraints.is_empty());

            assert!(external);
            assert_eq!(FileFormat::TEXTFILE, file_format.unwrap());
            assert_eq!("/tmp/example.csv", location.unwrap());

            assert_eq!(with_options, vec![]);
            assert!(!if_not_exists);
        }
        _ => unreachable!(),
    }
}

#[test]
fn parse_create_table_empty() {
    // Zero-column tables are weird, but supported by at least PostgreSQL.
    let _ = verified_stmt("CREATE TABLE t ()");
}

#[test]
fn parse_alter_table_constraints() {
    check_one("CONSTRAINT address_pkey PRIMARY KEY (address_id)");
    check_one("CONSTRAINT uk_task UNIQUE (report_date, task_id)");
    check_one(
        "CONSTRAINT customer_address_id_fkey FOREIGN KEY (address_id) \
         REFERENCES public.address(address_id)",
    );
    check_one("CONSTRAINT ck CHECK (rtrim(ltrim(REF_CODE)) <> '')");

    check_one("PRIMARY KEY (foo, bar)");
    check_one("UNIQUE (id)");
    check_one("FOREIGN KEY (foo, bar) REFERENCES AnotherTable(foo, bar)");
    check_one("CHECK (end_date > start_date OR end_date IS NULL)");

    fn check_one(constraint_text: &str) {
        match verified_stmt(&format!("ALTER TABLE tab ADD {}", constraint_text)) {
            Statement::AlterTable {
                name,
                operation: AlterTableOperation::AddConstraint(constraint),
            } => {
                assert_eq!("tab", name.to_string());
                assert_eq!(constraint_text, constraint.to_string());
            }
            _ => unreachable!(),
        }
        verified_stmt(&format!("CREATE TABLE foo (id int, {})", constraint_text));
    }
}

#[test]
fn parse_bad_constraint() {
    let res = parse_sql_statements("ALTER TABLE tab ADD");
    assert_eq!(
        ParserError::ParserError(
            "Expected a constraint in ALTER TABLE .. ADD, found: EOF".to_string()
        ),
        res.unwrap_err()
    );

    let res = parse_sql_statements("CREATE TABLE tab (foo int,");
    assert_eq!(
        ParserError::ParserError(
            "Expected column name or constraint definition, found: EOF".to_string()
        ),
        res.unwrap_err()
    );
}

#[test]
fn parse_scalar_function_in_projection() {
    let sql = "SELECT sqrt(id) FROM foo";
    let select = verified_only_select(sql);
    assert_eq!(
        &Expr::Function(Function {
            name: ObjectName(vec![Ident::new("sqrt")]),
            args: vec![Expr::Identifier(Ident::new("id"))],
            over: None,
            distinct: false,
        }),
        expr_from_projection(only(&select.projection))
    );
}

#[test]
fn parse_window_functions() {
    let sql = "SELECT row_number() OVER (ORDER BY dt DESC), \
               sum(foo) OVER (PARTITION BY a, b ORDER BY c, d \
               ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW), \
               avg(bar) OVER (ORDER BY a \
               RANGE BETWEEN 1 PRECEDING AND 1 FOLLOWING), \
               max(baz) OVER (ORDER BY a \
               ROWS UNBOUNDED PRECEDING) \
               FROM foo";
    let select = verified_only_select(sql);
    assert_eq!(4, select.projection.len());
    assert_eq!(
        &Expr::Function(Function {
            name: ObjectName(vec![Ident::new("row_number")]),
            args: vec![],
            over: Some(WindowSpec {
                partition_by: vec![],
                order_by: vec![OrderByExpr {
                    expr: Expr::Identifier(Ident::new("dt")),
                    asc: Some(false)
                }],
                window_frame: None,
            }),
            distinct: false,
        }),
        expr_from_projection(&select.projection[0])
    );
}

#[test]
fn parse_aggregate_with_group_by() {
    let sql = "SELECT a, COUNT(1), MIN(b), MAX(b) FROM foo GROUP BY a";
    let _ast = verified_only_select(sql);
    //TODO: assertions
}

#[test]
fn parse_literal_decimal() {
    // These numbers were explicitly chosen to not roundtrip if represented as
    // f64s (i.e., as 64-bit binary floating point numbers).
    let sql = "SELECT 0.300000000000000004, 9007199254740993.0";
    let select = verified_only_select(sql);
    assert_eq!(2, select.projection.len());
    assert_eq!(
        &Expr::Value(number("0.300000000000000004")),
        expr_from_projection(&select.projection[0]),
    );
    assert_eq!(
        &Expr::Value(number("9007199254740993.0")),
        expr_from_projection(&select.projection[1]),
    )
}

#[test]
fn parse_literal_string() {
    let sql = "SELECT 'one', N'national string', X'deadBEEF'";
    let select = verified_only_select(sql);
    assert_eq!(3, select.projection.len());
    assert_eq!(
        &Expr::Value(Value::SingleQuotedString("one".to_string())),
        expr_from_projection(&select.projection[0])
    );
    assert_eq!(
        &Expr::Value(Value::NationalStringLiteral("national string".to_string())),
        expr_from_projection(&select.projection[1])
    );
    assert_eq!(
        &Expr::Value(Value::HexStringLiteral("deadBEEF".to_string())),
        expr_from_projection(&select.projection[2])
    );

    one_statement_parses_to("SELECT x'deadBEEF'", "SELECT X'deadBEEF'");
}

#[test]
fn parse_literal_date() {
    let sql = "SELECT DATE '1999-01-01'";
    let select = verified_only_select(sql);
    assert_eq!(
        &Expr::Value(Value::Date("1999-01-01".into())),
        expr_from_projection(only(&select.projection)),
    );
}

#[test]
fn parse_literal_time() {
    let sql = "SELECT TIME '01:23:34'";
    let select = verified_only_select(sql);
    assert_eq!(
        &Expr::Value(Value::Time("01:23:34".into())),
        expr_from_projection(only(&select.projection)),
    );
}

#[test]
fn parse_literal_timestamp() {
    let sql = "SELECT TIMESTAMP '1999-01-01 01:23:34'";
    let select = verified_only_select(sql);
    assert_eq!(
        &Expr::Value(Value::Timestamp("1999-01-01 01:23:34".into())),
        expr_from_projection(only(&select.projection)),
    );
}

#[test]
fn parse_literal_interval() {
    let sql = "SELECT INTERVAL '1-1' YEAR TO MONTH";
    let select = verified_only_select(sql);
    assert_eq!(
        &Expr::Value(Value::Interval {
            value: "1-1".into(),
            leading_field: DateTimeField::Year,
            leading_precision: None,
            last_field: Some(DateTimeField::Month),
            fractional_seconds_precision: None,
        }),
        expr_from_projection(only(&select.projection)),
    );

    let sql = "SELECT INTERVAL '01:01.01' MINUTE (5) TO SECOND (5)";
    let select = verified_only_select(sql);
    assert_eq!(
        &Expr::Value(Value::Interval {
            value: "01:01.01".into(),
            leading_field: DateTimeField::Minute,
            leading_precision: Some(5),
            last_field: Some(DateTimeField::Second),
            fractional_seconds_precision: Some(5),
        }),
        expr_from_projection(only(&select.projection)),
    );

    let sql = "SELECT INTERVAL '1' SECOND (5, 4)";
    let select = verified_only_select(sql);
    assert_eq!(
        &Expr::Value(Value::Interval {
            value: "1".into(),
            leading_field: DateTimeField::Second,
            leading_precision: Some(5),
            last_field: None,
            fractional_seconds_precision: Some(4),
        }),
        expr_from_projection(only(&select.projection)),
    );

    let sql = "SELECT INTERVAL '10' HOUR";
    let select = verified_only_select(sql);
    assert_eq!(
        &Expr::Value(Value::Interval {
            value: "10".into(),
            leading_field: DateTimeField::Hour,
            leading_precision: None,
            last_field: None,
            fractional_seconds_precision: None,
        }),
        expr_from_projection(only(&select.projection)),
    );

    let sql = "SELECT INTERVAL '10' HOUR (1)";
    let select = verified_only_select(sql);
    assert_eq!(
        &Expr::Value(Value::Interval {
            value: "10".into(),
            leading_field: DateTimeField::Hour,
            leading_precision: Some(1),
            last_field: None,
            fractional_seconds_precision: None,
        }),
        expr_from_projection(only(&select.projection)),
    );

    let result = parse_sql_statements("SELECT INTERVAL '1' SECOND TO SECOND");
    assert_eq!(
        ParserError::ParserError("Expected end of statement, found: SECOND".to_string()),
        result.unwrap_err(),
    );

    let result = parse_sql_statements("SELECT INTERVAL '10' HOUR (1) TO HOUR (2)");
    assert_eq!(
        ParserError::ParserError("Expected end of statement, found: (".to_string()),
        result.unwrap_err(),
    );

    verified_only_select("SELECT INTERVAL '1' YEAR");
    verified_only_select("SELECT INTERVAL '1' MONTH");
    verified_only_select("SELECT INTERVAL '1' DAY");
    verified_only_select("SELECT INTERVAL '1' HOUR");
    verified_only_select("SELECT INTERVAL '1' MINUTE");
    verified_only_select("SELECT INTERVAL '1' SECOND");
    verified_only_select("SELECT INTERVAL '1' YEAR TO MONTH");
    verified_only_select("SELECT INTERVAL '1' DAY TO HOUR");
    verified_only_select("SELECT INTERVAL '1' DAY TO MINUTE");
    verified_only_select("SELECT INTERVAL '1' DAY TO SECOND");
    verified_only_select("SELECT INTERVAL '1' HOUR TO MINUTE");
    verified_only_select("SELECT INTERVAL '1' HOUR TO SECOND");
    verified_only_select("SELECT INTERVAL '1' MINUTE TO SECOND");
}

#[test]
fn parse_simple_math_expr_plus() {
    let sql = "SELECT a + b, 2 + a, 2.5 + a, a_f + b_f, 2 + a_f, 2.5 + a_f FROM c";
    verified_only_select(sql);
}

#[test]
fn parse_simple_math_expr_minus() {
    let sql = "SELECT a - b, 2 - a, 2.5 - a, a_f - b_f, 2 - a_f, 2.5 - a_f FROM c";
    verified_only_select(sql);
}

#[test]
fn parse_delimited_identifiers() {
    // check that quoted identifiers in any position remain quoted after serialization
    let select = verified_only_select(
        r#"SELECT "alias"."bar baz", "myfun"(), "simple id" AS "column alias" FROM "a table" AS "alias""#,
    );
    // check FROM
    match only(select.from).relation {
        TableFactor::Table {
            name,
            alias,
            args,
            with_hints,
        } => {
            assert_eq!(vec![Ident::with_quote('"', "a table")], name.0);
            assert_eq!(Ident::with_quote('"', "alias"), alias.unwrap().name);
            assert!(args.is_empty());
            assert!(with_hints.is_empty());
        }
        _ => panic!("Expecting TableFactor::Table"),
    }
    // check SELECT
    assert_eq!(3, select.projection.len());
    assert_eq!(
        &Expr::CompoundIdentifier(vec![
            Ident::with_quote('"', "alias"),
            Ident::with_quote('"', "bar baz")
        ]),
        expr_from_projection(&select.projection[0]),
    );
    assert_eq!(
        &Expr::Function(Function {
            name: ObjectName(vec![Ident::with_quote('"', "myfun")]),
            args: vec![],
            over: None,
            distinct: false,
        }),
        expr_from_projection(&select.projection[1]),
    );
    match &select.projection[2] {
        SelectItem::ExprWithAlias { expr, alias } => {
            assert_eq!(&Expr::Identifier(Ident::with_quote('"', "simple id")), expr);
            assert_eq!(&Ident::with_quote('"', "column alias"), alias);
        }
        _ => panic!("Expected ExprWithAlias"),
    }

    verified_stmt(r#"CREATE TABLE "foo" ("bar" "int")"#);
    verified_stmt(r#"ALTER TABLE foo ADD CONSTRAINT "bar" PRIMARY KEY (baz)"#);
    //TODO verified_stmt(r#"UPDATE foo SET "bar" = 5"#);
}

#[test]
fn parse_parens() {
    use self::BinaryOperator::*;
    use self::Expr::*;
    let sql = "(a + b) - (c + d)";
    assert_eq!(
        BinaryOp {
            left: Box::new(Nested(Box::new(BinaryOp {
                left: Box::new(Identifier(Ident::new("a"))),
                op: Plus,
                right: Box::new(Identifier(Ident::new("b")))
            }))),
            op: Minus,
            right: Box::new(Nested(Box::new(BinaryOp {
                left: Box::new(Identifier(Ident::new("c"))),
                op: Plus,
                right: Box::new(Identifier(Ident::new("d")))
            })))
        },
        verified_expr(sql)
    );
}

#[test]
fn parse_searched_case_expr() {
    let sql = "SELECT CASE WHEN bar IS NULL THEN 'null' WHEN bar = 0 THEN '=0' WHEN bar >= 0 THEN '>=0' ELSE '<0' END FROM foo";
    use self::BinaryOperator::*;
    use self::Expr::{BinaryOp, Case, Identifier, IsNull};
    let select = verified_only_select(sql);
    assert_eq!(
        &Case {
            operand: None,
            conditions: vec![
                IsNull(Box::new(Identifier(Ident::new("bar")))),
                BinaryOp {
                    left: Box::new(Identifier(Ident::new("bar"))),
                    op: Eq,
                    right: Box::new(Expr::Value(number("0")))
                },
                BinaryOp {
                    left: Box::new(Identifier(Ident::new("bar"))),
                    op: GtEq,
                    right: Box::new(Expr::Value(number("0")))
                }
            ],
            results: vec![
                Expr::Value(Value::SingleQuotedString("null".to_string())),
                Expr::Value(Value::SingleQuotedString("=0".to_string())),
                Expr::Value(Value::SingleQuotedString(">=0".to_string()))
            ],
            else_result: Some(Box::new(Expr::Value(Value::SingleQuotedString(
                "<0".to_string()
            ))))
        },
        expr_from_projection(only(&select.projection)),
    );
}

#[test]
fn parse_simple_case_expr() {
    // ANSI calls a CASE expression with an operand "<simple case>"
    let sql = "SELECT CASE foo WHEN 1 THEN 'Y' ELSE 'N' END";
    let select = verified_only_select(sql);
    use self::Expr::{Case, Identifier};
    assert_eq!(
        &Case {
            operand: Some(Box::new(Identifier(Ident::new("foo")))),
            conditions: vec![Expr::Value(number("1"))],
            results: vec![Expr::Value(Value::SingleQuotedString("Y".to_string())),],
            else_result: Some(Box::new(Expr::Value(Value::SingleQuotedString(
                "N".to_string()
            ))))
        },
        expr_from_projection(only(&select.projection)),
    );
}

#[test]
fn parse_from_advanced() {
    let sql = "SELECT * FROM fn(1, 2) AS foo, schema.bar AS bar WITH (NOLOCK)";
    let _select = verified_only_select(sql);
}

#[test]
fn parse_implicit_join() {
    let sql = "SELECT * FROM t1, t2";
    let select = verified_only_select(sql);
    assert_eq!(
        vec![
            TableWithJoins {
                relation: TableFactor::Table {
                    name: ObjectName(vec!["t1".into()]),
                    alias: None,
                    args: vec![],
                    with_hints: vec![],
                },
                joins: vec![],
            },
            TableWithJoins {
                relation: TableFactor::Table {
                    name: ObjectName(vec!["t2".into()]),
                    alias: None,
                    args: vec![],
                    with_hints: vec![],
                },
                joins: vec![],
            }
        ],
        select.from,
    );

    let sql = "SELECT * FROM t1a NATURAL JOIN t1b, t2a NATURAL JOIN t2b";
    let select = verified_only_select(sql);
    assert_eq!(
        vec![
            TableWithJoins {
                relation: TableFactor::Table {
                    name: ObjectName(vec!["t1a".into()]),
                    alias: None,
                    args: vec![],
                    with_hints: vec![],
                },
                joins: vec![Join {
                    relation: TableFactor::Table {
                        name: ObjectName(vec!["t1b".into()]),
                        alias: None,
                        args: vec![],
                        with_hints: vec![],
                    },
                    join_operator: JoinOperator::Inner(JoinConstraint::Natural),
                }]
            },
            TableWithJoins {
                relation: TableFactor::Table {
                    name: ObjectName(vec!["t2a".into()]),
                    alias: None,
                    args: vec![],
                    with_hints: vec![],
                },
                joins: vec![Join {
                    relation: TableFactor::Table {
                        name: ObjectName(vec!["t2b".into()]),
                        alias: None,
                        args: vec![],
                        with_hints: vec![],
                    },
                    join_operator: JoinOperator::Inner(JoinConstraint::Natural),
                }]
            }
        ],
        select.from,
    );
}

#[test]
fn parse_cross_join() {
    let sql = "SELECT * FROM t1 CROSS JOIN t2";
    let select = verified_only_select(sql);
    assert_eq!(
        Join {
            relation: TableFactor::Table {
                name: ObjectName(vec![Ident::new("t2")]),
                alias: None,
                args: vec![],
                with_hints: vec![],
            },
            join_operator: JoinOperator::CrossJoin
        },
        only(only(select.from).joins),
    );
}

fn table_alias(name: impl Into<String>) -> Option<TableAlias> {
    Some(TableAlias {
        name: Ident::new(name),
        columns: vec![],
    })
}

#[test]
fn parse_joins_on() {
    fn join_with_constraint(
        relation: impl Into<String>,
        alias: Option<TableAlias>,
        f: impl Fn(JoinConstraint) -> JoinOperator,
    ) -> Join {
        Join {
            relation: TableFactor::Table {
                name: ObjectName(vec![Ident::new(relation.into())]),
                alias,
                args: vec![],
                with_hints: vec![],
            },
            join_operator: f(JoinConstraint::On(Expr::BinaryOp {
                left: Box::new(Expr::Identifier("c1".into())),
                op: BinaryOperator::Eq,
                right: Box::new(Expr::Identifier("c2".into())),
            })),
        }
    }
    // Test parsing of aliases
    assert_eq!(
        only(&verified_only_select("SELECT * FROM t1 JOIN t2 AS foo ON c1 = c2").from).joins,
        vec![join_with_constraint(
            "t2",
            table_alias("foo"),
            JoinOperator::Inner
        )]
    );
    one_statement_parses_to(
        "SELECT * FROM t1 JOIN t2 foo ON c1 = c2",
        "SELECT * FROM t1 JOIN t2 AS foo ON c1 = c2",
    );
    // Test parsing of different join operators
    assert_eq!(
        only(&verified_only_select("SELECT * FROM t1 JOIN t2 ON c1 = c2").from).joins,
        vec![join_with_constraint("t2", None, JoinOperator::Inner)]
    );
    assert_eq!(
        only(&verified_only_select("SELECT * FROM t1 LEFT JOIN t2 ON c1 = c2").from).joins,
        vec![join_with_constraint("t2", None, JoinOperator::LeftOuter)]
    );
    assert_eq!(
        only(&verified_only_select("SELECT * FROM t1 RIGHT JOIN t2 ON c1 = c2").from).joins,
        vec![join_with_constraint("t2", None, JoinOperator::RightOuter)]
    );
    assert_eq!(
        only(&verified_only_select("SELECT * FROM t1 FULL JOIN t2 ON c1 = c2").from).joins,
        vec![join_with_constraint("t2", None, JoinOperator::FullOuter)]
    );
}

#[test]
fn parse_joins_using() {
    fn join_with_constraint(
        relation: impl Into<String>,
        alias: Option<TableAlias>,
        f: impl Fn(JoinConstraint) -> JoinOperator,
    ) -> Join {
        Join {
            relation: TableFactor::Table {
                name: ObjectName(vec![Ident::new(relation.into())]),
                alias,
                args: vec![],
                with_hints: vec![],
            },
            join_operator: f(JoinConstraint::Using(vec!["c1".into()])),
        }
    }
    // Test parsing of aliases
    assert_eq!(
        only(&verified_only_select("SELECT * FROM t1 JOIN t2 AS foo USING(c1)").from).joins,
        vec![join_with_constraint(
            "t2",
            table_alias("foo"),
            JoinOperator::Inner
        )]
    );
    one_statement_parses_to(
        "SELECT * FROM t1 JOIN t2 foo USING(c1)",
        "SELECT * FROM t1 JOIN t2 AS foo USING(c1)",
    );
    // Test parsing of different join operators
    assert_eq!(
        only(&verified_only_select("SELECT * FROM t1 JOIN t2 USING(c1)").from).joins,
        vec![join_with_constraint("t2", None, JoinOperator::Inner)]
    );
    assert_eq!(
        only(&verified_only_select("SELECT * FROM t1 LEFT JOIN t2 USING(c1)").from).joins,
        vec![join_with_constraint("t2", None, JoinOperator::LeftOuter)]
    );
    assert_eq!(
        only(&verified_only_select("SELECT * FROM t1 RIGHT JOIN t2 USING(c1)").from).joins,
        vec![join_with_constraint("t2", None, JoinOperator::RightOuter)]
    );
    assert_eq!(
        only(&verified_only_select("SELECT * FROM t1 FULL JOIN t2 USING(c1)").from).joins,
        vec![join_with_constraint("t2", None, JoinOperator::FullOuter)]
    );
}

#[test]
fn parse_natural_join() {
    fn natural_join(f: impl Fn(JoinConstraint) -> JoinOperator) -> Join {
        Join {
            relation: TableFactor::Table {
                name: ObjectName(vec![Ident::new("t2")]),
                alias: None,
                args: vec![],
                with_hints: vec![],
            },
            join_operator: f(JoinConstraint::Natural),
        }
    }
    assert_eq!(
        only(&verified_only_select("SELECT * FROM t1 NATURAL JOIN t2").from).joins,
        vec![natural_join(JoinOperator::Inner)]
    );
    assert_eq!(
        only(&verified_only_select("SELECT * FROM t1 NATURAL LEFT JOIN t2").from).joins,
        vec![natural_join(JoinOperator::LeftOuter)]
    );
    assert_eq!(
        only(&verified_only_select("SELECT * FROM t1 NATURAL RIGHT JOIN t2").from).joins,
        vec![natural_join(JoinOperator::RightOuter)]
    );
    assert_eq!(
        only(&verified_only_select("SELECT * FROM t1 NATURAL FULL JOIN t2").from).joins,
        vec![natural_join(JoinOperator::FullOuter)]
    );

    let sql = "SELECT * FROM t1 natural";
    assert_eq!(
        ParserError::ParserError("Expected a join type after NATURAL, found: EOF".to_string()),
        parse_sql_statements(sql).unwrap_err(),
    );
}

#[test]
fn parse_complex_join() {
    let sql = "SELECT c1, c2 FROM t1, t4 JOIN t2 ON t2.c = t1.c LEFT JOIN t3 USING(q, c) WHERE t4.c = t1.c";
    verified_only_select(sql);
}

#[test]
fn parse_join_nesting() {
    fn table(name: impl Into<String>) -> TableFactor {
        TableFactor::Table {
            name: ObjectName(vec![Ident::new(name.into())]),
            alias: None,
            args: vec![],
            with_hints: vec![],
        }
    }

    fn join(relation: TableFactor) -> Join {
        Join {
            relation,
            join_operator: JoinOperator::Inner(JoinConstraint::Natural),
        }
    }

    macro_rules! nest {
        ($base:expr $(, $join:expr)*) => {
            TableFactor::NestedJoin(Box::new(TableWithJoins {
                relation: $base,
                joins: vec![$(join($join)),*]
            }))
        };
    }

    let sql = "SELECT * FROM a NATURAL JOIN (b NATURAL JOIN (c NATURAL JOIN d NATURAL JOIN e)) \
               NATURAL JOIN (f NATURAL JOIN (g NATURAL JOIN h))";
    assert_eq!(
        only(&verified_only_select(sql).from).joins,
        vec![
            join(nest!(table("b"), nest!(table("c"), table("d"), table("e")))),
            join(nest!(table("f"), nest!(table("g"), table("h"))))
        ],
    );

    let sql = "SELECT * FROM (a NATURAL JOIN b) NATURAL JOIN c";
    let select = verified_only_select(sql);
    let from = only(select.from);
    assert_eq!(from.relation, nest!(table("a"), table("b")));
    assert_eq!(from.joins, vec![join(table("c"))]);

    let sql = "SELECT * FROM (((a NATURAL JOIN b)))";
    let select = verified_only_select(sql);
    let from = only(select.from);
    assert_eq!(from.relation, nest!(nest!(nest!(table("a"), table("b")))));
    assert_eq!(from.joins, vec![]);

    let sql = "SELECT * FROM a NATURAL JOIN (((b NATURAL JOIN c)))";
    let select = verified_only_select(sql);
    let from = only(select.from);
    assert_eq!(from.relation, table("a"));
    assert_eq!(
        from.joins,
        vec![join(nest!(nest!(nest!(table("b"), table("c")))))]
    );

    // Parenthesized table names are non-standard, but supported in Snowflake SQL
    let sql = "SELECT * FROM (a NATURAL JOIN (b))";
    let select = verified_only_select(sql);
    let from = only(select.from);

    assert_eq!(from.relation, nest!(table("a"), nest!(table("b"))));

    // Double parentheses around table names are non-standard, but supported in Snowflake SQL
    let sql = "SELECT * FROM (a NATURAL JOIN ((b)))";
    let select = verified_only_select(sql);
    let from = only(select.from);

    assert_eq!(from.relation, nest!(table("a"), nest!(nest!(table("b")))));
}

#[test]
fn parse_join_syntax_variants() {
    one_statement_parses_to(
        "SELECT c1 FROM t1 INNER JOIN t2 USING(c1)",
        "SELECT c1 FROM t1 JOIN t2 USING(c1)",
    );
    one_statement_parses_to(
        "SELECT c1 FROM t1 LEFT OUTER JOIN t2 USING(c1)",
        "SELECT c1 FROM t1 LEFT JOIN t2 USING(c1)",
    );
    one_statement_parses_to(
        "SELECT c1 FROM t1 RIGHT OUTER JOIN t2 USING(c1)",
        "SELECT c1 FROM t1 RIGHT JOIN t2 USING(c1)",
    );
    one_statement_parses_to(
        "SELECT c1 FROM t1 FULL OUTER JOIN t2 USING(c1)",
        "SELECT c1 FROM t1 FULL JOIN t2 USING(c1)",
    );

    let res = parse_sql_statements("SELECT * FROM a OUTER JOIN b ON 1");
    assert_eq!(
        ParserError::ParserError("Expected APPLY, found: JOIN".to_string()),
        res.unwrap_err()
    );
}

#[test]
fn parse_ctes() {
    let cte_sqls = vec!["SELECT 1 AS foo", "SELECT 2 AS bar"];
    let with = &format!(
        "WITH a AS ({}), b AS ({}) SELECT foo + bar FROM a, b",
        cte_sqls[0], cte_sqls[1]
    );

    fn assert_ctes_in_select(expected: &[&str], sel: &Query) {
        let mut i = 0;
        for exp in expected {
            let Cte { alias, query } = &sel.ctes[i];
            assert_eq!(*exp, query.to_string());
            assert_eq!(
                if i == 0 {
                    Ident::new("a")
                } else {
                    Ident::new("b")
                },
                alias.name
            );
            assert!(alias.columns.is_empty());
            i += 1;
        }
    }

    // Top-level CTE
    assert_ctes_in_select(&cte_sqls, &verified_query(with));
    // CTE in a subquery
    let sql = &format!("SELECT ({})", with);
    let select = verified_only_select(sql);
    match expr_from_projection(only(&select.projection)) {
        Expr::Subquery(ref subquery) => {
            assert_ctes_in_select(&cte_sqls, subquery.as_ref());
        }
        _ => panic!("Expected subquery"),
    }
    // CTE in a derived table
    let sql = &format!("SELECT * FROM ({})", with);
    let select = verified_only_select(sql);
    match only(select.from).relation {
        TableFactor::Derived { subquery, .. } => {
            assert_ctes_in_select(&cte_sqls, subquery.as_ref())
        }
        _ => panic!("Expected derived table"),
    }
    // CTE in a view
    let sql = &format!("CREATE VIEW v AS {}", with);
    match verified_stmt(sql) {
        Statement::CreateView { query, .. } => assert_ctes_in_select(&cte_sqls, &query),
        _ => panic!("Expected CREATE VIEW"),
    }
    // CTE in a CTE...
    let sql = &format!("WITH outer_cte AS ({}) SELECT * FROM outer_cte", with);
    let select = verified_query(sql);
    assert_ctes_in_select(&cte_sqls, &only(&select.ctes).query);
}

#[test]
fn parse_cte_renamed_columns() {
    let sql = "WITH cte (col1, col2) AS (SELECT foo, bar FROM baz) SELECT * FROM cte";
    let query = all_dialects().verified_query(sql);
    assert_eq!(
        vec![Ident::new("col1"), Ident::new("col2")],
        query.ctes.first().unwrap().alias.columns
    );
}

#[test]
fn parse_derived_tables() {
    let sql = "SELECT a.x, b.y FROM (SELECT x FROM foo) AS a CROSS JOIN (SELECT y FROM bar) AS b";
    let _ = verified_only_select(sql);
    //TODO: add assertions

    let sql = "SELECT a.x, b.y \
               FROM (SELECT x FROM foo) AS a (x) \
               CROSS JOIN (SELECT y FROM bar) AS b (y)";
    let _ = verified_only_select(sql);
    //TODO: add assertions

    let sql = "SELECT * FROM (((SELECT 1)))";
    let _ = verified_only_select(sql);
    // TODO: add assertions

    let sql = "SELECT * FROM t NATURAL JOIN (((SELECT 1)))";
    let _ = verified_only_select(sql);
    // TODO: add assertions

    let sql = "SELECT * FROM (((SELECT 1) UNION (SELECT 2)) AS t1 NATURAL JOIN t2)";
    let select = verified_only_select(sql);
    let from = only(select.from);
    assert_eq!(
        from.relation,
        TableFactor::NestedJoin(Box::new(TableWithJoins {
            relation: TableFactor::Derived {
                lateral: false,
                subquery: Box::new(verified_query("(SELECT 1) UNION (SELECT 2)")),
                alias: Some(TableAlias {
                    name: "t1".into(),
                    columns: vec![],
                })
            },
            joins: vec![Join {
                relation: TableFactor::Table {
                    name: ObjectName(vec!["t2".into()]),
                    alias: None,
                    args: vec![],
                    with_hints: vec![],
                },
                join_operator: JoinOperator::Inner(JoinConstraint::Natural),
            }],
        }))
    );

    // Nesting a subquery in parentheses is non-standard, but supported in Snowflake SQL
    let sql = "SELECT * FROM ((SELECT 1) AS t)";
    let select = verified_only_select(sql);
    let from = only(select.from);

    assert_eq!(
        from.relation,
        TableFactor::NestedJoin(Box::new(TableWithJoins {
            relation: TableFactor::Derived {
                lateral: false,
                subquery: Box::new(verified_query("SELECT 1")),
                alias: Some(TableAlias {
                    name: "t".into(),
                    columns: vec![],
                })
            },
            joins: Vec::new(),
        }))
    );
}

#[test]
fn parse_union() {
    // TODO: add assertions
    verified_stmt("SELECT 1 UNION SELECT 2");
    verified_stmt("SELECT 1 UNION ALL SELECT 2");
    verified_stmt("SELECT 1 EXCEPT SELECT 2");
    verified_stmt("SELECT 1 EXCEPT ALL SELECT 2");
    verified_stmt("SELECT 1 INTERSECT SELECT 2");
    verified_stmt("SELECT 1 INTERSECT ALL SELECT 2");
    verified_stmt("SELECT 1 UNION SELECT 2 UNION SELECT 3");
    verified_stmt("SELECT 1 EXCEPT SELECT 2 UNION SELECT 3"); // Union[Except[1,2], 3]
    verified_stmt("SELECT 1 INTERSECT (SELECT 2 EXCEPT SELECT 3)");
    verified_stmt("WITH cte AS (SELECT 1 AS foo) (SELECT foo FROM cte ORDER BY 1 LIMIT 1)");
    verified_stmt("SELECT 1 UNION (SELECT 2 ORDER BY 1 LIMIT 1)");
    verified_stmt("SELECT 1 UNION SELECT 2 INTERSECT SELECT 3"); // Union[1, Intersect[2,3]]
    verified_stmt("SELECT foo FROM tab UNION SELECT bar FROM TAB");
    verified_stmt("(SELECT * FROM new EXCEPT SELECT * FROM old) UNION ALL (SELECT * FROM old EXCEPT SELECT * FROM new) ORDER BY 1");
}

#[test]
fn parse_values() {
    verified_stmt("SELECT * FROM (VALUES (1), (2), (3))");
    verified_stmt("SELECT * FROM (VALUES (1), (2), (3)), (VALUES (1, 2, 3))");
    verified_stmt("SELECT * FROM (VALUES (1)) UNION VALUES (1)");
}

#[test]
fn parse_multiple_statements() {
    fn test_with(sql1: &str, sql2_kw: &str, sql2_rest: &str) {
        // Check that a string consisting of two statements delimited by a semicolon
        // parses the same as both statements individually:
        let res = parse_sql_statements(&(sql1.to_owned() + ";" + sql2_kw + sql2_rest));
        assert_eq!(
            vec![
                one_statement_parses_to(&sql1, ""),
                one_statement_parses_to(&(sql2_kw.to_owned() + sql2_rest), ""),
            ],
            res.unwrap()
        );
        // Check that extra semicolon at the end is stripped by normalization:
        one_statement_parses_to(&(sql1.to_owned() + ";"), sql1);
        // Check that forgetting the semicolon results in an error:
        let res = parse_sql_statements(&(sql1.to_owned() + " " + sql2_kw + sql2_rest));
        assert_eq!(
            ParserError::ParserError("Expected end of statement, found: ".to_string() + sql2_kw),
            res.unwrap_err()
        );
    }
    test_with("SELECT foo", "SELECT", " bar");
    // ensure that SELECT/WITH is not parsed as a table or column alias if ';'
    // separating the statements is omitted:
    test_with("SELECT foo FROM baz", "SELECT", " bar");
    test_with("SELECT foo", "WITH", " cte AS (SELECT 1 AS s) SELECT bar");
    test_with(
        "SELECT foo FROM baz",
        "WITH",
        " cte AS (SELECT 1 AS s) SELECT bar",
    );
    test_with("DELETE FROM foo", "SELECT", " bar");
    test_with("INSERT INTO foo VALUES (1)", "SELECT", " bar");
    test_with("CREATE TABLE foo (baz int)", "SELECT", " bar");
    // Make sure that empty statements do not cause an error:
    let res = parse_sql_statements(";;");
    assert_eq!(0, res.unwrap().len());
}

#[test]
fn parse_scalar_subqueries() {
    let sql = "(SELECT 1) + (SELECT 2)";
    assert_matches!(verified_expr(sql), Expr::BinaryOp {
        op: BinaryOperator::Plus, ..
        //left: box Subquery { .. },
        //right: box Subquery { .. },
    });
}

#[test]
fn parse_exists_subquery() {
    let expected_inner = verified_query("SELECT 1");
    let sql = "SELECT * FROM t WHERE EXISTS (SELECT 1)";
    let select = verified_only_select(sql);
    assert_eq!(
        Expr::Exists(Box::new(expected_inner.clone())),
        select.selection.unwrap(),
    );

    let sql = "SELECT * FROM t WHERE NOT EXISTS (SELECT 1)";
    let select = verified_only_select(sql);
    assert_eq!(
        Expr::UnaryOp {
            op: UnaryOperator::Not,
            expr: Box::new(Expr::Exists(Box::new(expected_inner))),
        },
        select.selection.unwrap(),
    );

    verified_stmt("SELECT * FROM t WHERE EXISTS (WITH u AS (SELECT 1) SELECT * FROM u)");
    verified_stmt("SELECT EXISTS (SELECT 1)");

    let res = parse_sql_statements("SELECT EXISTS (");
    assert_eq!(
        ParserError::ParserError(
            "Expected SELECT, VALUES, or a subquery in the query body, found: EOF".to_string()
        ),
        res.unwrap_err(),
    );

    let res = parse_sql_statements("SELECT EXISTS (NULL)");
    assert_eq!(
        ParserError::ParserError(
            "Expected SELECT, VALUES, or a subquery in the query body, found: NULL".to_string()
        ),
        res.unwrap_err(),
    );
}

#[test]
fn parse_create_view() {
    let sql = "CREATE VIEW myschema.myview AS SELECT foo FROM bar";
    match verified_stmt(sql) {
        Statement::CreateView {
            name,
            columns,
            query,
            materialized,
            with_options,
        } => {
            assert_eq!("myschema.myview", name.to_string());
            assert_eq!(Vec::<Ident>::new(), columns);
            assert_eq!("SELECT foo FROM bar", query.to_string());
            assert!(!materialized);
            assert_eq!(with_options, vec![]);
        }
        _ => unreachable!(),
    }
}

#[test]
fn parse_create_view_with_options() {
    let sql = "CREATE VIEW v WITH (foo = 'bar', a = 123) AS SELECT 1";
    match verified_stmt(sql) {
        Statement::CreateView { with_options, .. } => {
            assert_eq!(
                vec![
                    SqlOption {
                        name: "foo".into(),
                        value: Value::SingleQuotedString("bar".into())
                    },
                    SqlOption {
                        name: "a".into(),
                        value: number("123")
                    },
                ],
                with_options
            );
        }
        _ => unreachable!(),
    }
}

#[test]
fn parse_create_view_with_columns() {
    let sql = "CREATE VIEW v (has, cols) AS SELECT 1, 2";
    match verified_stmt(sql) {
        Statement::CreateView {
            name,
            columns,
            with_options,
            query,
            materialized,
        } => {
            assert_eq!("v", name.to_string());
            assert_eq!(columns, vec![Ident::new("has"), Ident::new("cols")]);
            assert_eq!(with_options, vec![]);
            assert_eq!("SELECT 1, 2", query.to_string());
            assert!(!materialized);
        }
        _ => unreachable!(),
    }
}

#[test]
fn parse_create_materialized_view() {
    let sql = "CREATE MATERIALIZED VIEW myschema.myview AS SELECT foo FROM bar";
    match verified_stmt(sql) {
        Statement::CreateView {
            name,
            columns,
            query,
            materialized,
            with_options,
        } => {
            assert_eq!("myschema.myview", name.to_string());
            assert_eq!(Vec::<Ident>::new(), columns);
            assert_eq!("SELECT foo FROM bar", query.to_string());
            assert!(materialized);
            assert_eq!(with_options, vec![]);
        }
        _ => unreachable!(),
    }
}

#[test]
fn parse_drop_table() {
    let sql = "DROP TABLE foo";
    match verified_stmt(sql) {
        Statement::Drop {
            object_type,
            if_exists,
            names,
            cascade,
        } => {
            assert_eq!(false, if_exists);
            assert_eq!(ObjectType::Table, object_type);
            assert_eq!(
                vec!["foo"],
                names.iter().map(ToString::to_string).collect::<Vec<_>>()
            );
            assert_eq!(false, cascade);
        }
        _ => unreachable!(),
    }

    let sql = "DROP TABLE IF EXISTS foo, bar CASCADE";
    match verified_stmt(sql) {
        Statement::Drop {
            object_type,
            if_exists,
            names,
            cascade,
        } => {
            assert_eq!(true, if_exists);
            assert_eq!(ObjectType::Table, object_type);
            assert_eq!(
                vec!["foo", "bar"],
                names.iter().map(ToString::to_string).collect::<Vec<_>>()
            );
            assert_eq!(true, cascade);
        }
        _ => unreachable!(),
    }

    let sql = "DROP TABLE";
    assert_eq!(
        ParserError::ParserError("Expected identifier, found: EOF".to_string()),
        parse_sql_statements(sql).unwrap_err(),
    );

    let sql = "DROP TABLE IF EXISTS foo, bar CASCADE RESTRICT";
    assert_eq!(
        ParserError::ParserError("Cannot specify both CASCADE and RESTRICT in DROP".to_string()),
        parse_sql_statements(sql).unwrap_err(),
    );
}

#[test]
fn parse_drop_view() {
    let sql = "DROP VIEW myschema.myview";
    match verified_stmt(sql) {
        Statement::Drop {
            names, object_type, ..
        } => {
            assert_eq!(
                vec!["myschema.myview"],
                names.iter().map(ToString::to_string).collect::<Vec<_>>()
            );
            assert_eq!(ObjectType::View, object_type);
        }
        _ => unreachable!(),
    }
}

#[test]
fn parse_invalid_subquery_without_parens() {
    let res = parse_sql_statements("SELECT SELECT 1 FROM bar WHERE 1=1 FROM baz");
    assert_eq!(
        ParserError::ParserError("Expected end of statement, found: 1".to_string()),
        res.unwrap_err()
    );
}

#[test]
fn parse_offset() {
    let expect = Some(Offset {
        value: Expr::Value(number("2")),
        rows: OffsetRows::Rows,
    });
    let ast = verified_query("SELECT foo FROM bar OFFSET 2 ROWS");
    assert_eq!(ast.offset, expect);
    let ast = verified_query("SELECT foo FROM bar WHERE foo = 4 OFFSET 2 ROWS");
    assert_eq!(ast.offset, expect);
    let ast = verified_query("SELECT foo FROM bar ORDER BY baz OFFSET 2 ROWS");
    assert_eq!(ast.offset, expect);
    let ast = verified_query("SELECT foo FROM bar WHERE foo = 4 ORDER BY baz OFFSET 2 ROWS");
    assert_eq!(ast.offset, expect);
    let ast = verified_query("SELECT foo FROM (SELECT * FROM bar OFFSET 2 ROWS) OFFSET 2 ROWS");
    assert_eq!(ast.offset, expect);
    match ast.body {
        SetExpr::Select(s) => match only(s.from).relation {
            TableFactor::Derived { subquery, .. } => {
                assert_eq!(subquery.offset, expect);
            }
            _ => panic!("Test broke"),
        },
        _ => panic!("Test broke"),
    }
    let ast = verified_query("SELECT 'foo' OFFSET 0 ROWS");
    assert_eq!(
        ast.offset,
        Some(Offset {
            value: Expr::Value(number("0")),
            rows: OffsetRows::Rows,
        })
    );
    let ast = verified_query("SELECT 'foo' OFFSET 1 ROW");
    assert_eq!(
        ast.offset,
        Some(Offset {
            value: Expr::Value(number("1")),
            rows: OffsetRows::Row,
        })
    );
    let ast = verified_query("SELECT 'foo' OFFSET 1");
    assert_eq!(
        ast.offset,
        Some(Offset {
            value: Expr::Value(number("1")),
            rows: OffsetRows::None,
        })
    );
}

#[test]
fn parse_fetch() {
    let fetch_first_two_rows_only = Some(Fetch {
        with_ties: false,
        percent: false,
        quantity: Some(Expr::Value(number("2"))),
    });
    let ast = verified_query("SELECT foo FROM bar FETCH FIRST 2 ROWS ONLY");
    assert_eq!(ast.fetch, fetch_first_two_rows_only);
    let ast = verified_query("SELECT 'foo' FETCH FIRST 2 ROWS ONLY");
    assert_eq!(ast.fetch, fetch_first_two_rows_only);
    let ast = verified_query("SELECT foo FROM bar FETCH FIRST ROWS ONLY");
    assert_eq!(
        ast.fetch,
        Some(Fetch {
            with_ties: false,
            percent: false,
            quantity: None,
        })
    );
    let ast = verified_query("SELECT foo FROM bar WHERE foo = 4 FETCH FIRST 2 ROWS ONLY");
    assert_eq!(ast.fetch, fetch_first_two_rows_only);
    let ast = verified_query("SELECT foo FROM bar ORDER BY baz FETCH FIRST 2 ROWS ONLY");
    assert_eq!(ast.fetch, fetch_first_two_rows_only);
    let ast = verified_query(
        "SELECT foo FROM bar WHERE foo = 4 ORDER BY baz FETCH FIRST 2 ROWS WITH TIES",
    );
    assert_eq!(
        ast.fetch,
        Some(Fetch {
            with_ties: true,
            percent: false,
            quantity: Some(Expr::Value(number("2"))),
        })
    );
    let ast = verified_query("SELECT foo FROM bar FETCH FIRST 50 PERCENT ROWS ONLY");
    assert_eq!(
        ast.fetch,
        Some(Fetch {
            with_ties: false,
            percent: true,
            quantity: Some(Expr::Value(number("50"))),
        })
    );
    let ast = verified_query(
        "SELECT foo FROM bar WHERE foo = 4 ORDER BY baz OFFSET 2 ROWS FETCH FIRST 2 ROWS ONLY",
    );
    assert_eq!(
        ast.offset,
        Some(Offset {
            value: Expr::Value(number("2")),
            rows: OffsetRows::Rows,
        })
    );
    assert_eq!(ast.fetch, fetch_first_two_rows_only);
    let ast = verified_query(
        "SELECT foo FROM (SELECT * FROM bar FETCH FIRST 2 ROWS ONLY) FETCH FIRST 2 ROWS ONLY",
    );
    assert_eq!(ast.fetch, fetch_first_two_rows_only);
    match ast.body {
        SetExpr::Select(s) => match only(s.from).relation {
            TableFactor::Derived { subquery, .. } => {
                assert_eq!(subquery.fetch, fetch_first_two_rows_only);
            }
            _ => panic!("Test broke"),
        },
        _ => panic!("Test broke"),
    }
    let ast = verified_query("SELECT foo FROM (SELECT * FROM bar OFFSET 2 ROWS FETCH FIRST 2 ROWS ONLY) OFFSET 2 ROWS FETCH FIRST 2 ROWS ONLY");
    assert_eq!(
        ast.offset,
        Some(Offset {
            value: Expr::Value(number("2")),
            rows: OffsetRows::Rows,
        })
    );
    assert_eq!(ast.fetch, fetch_first_two_rows_only);
    match ast.body {
        SetExpr::Select(s) => match only(s.from).relation {
            TableFactor::Derived { subquery, .. } => {
                assert_eq!(
                    subquery.offset,
                    Some(Offset {
                        value: Expr::Value(number("2")),
                        rows: OffsetRows::Rows,
                    })
                );
                assert_eq!(subquery.fetch, fetch_first_two_rows_only);
            }
            _ => panic!("Test broke"),
        },
        _ => panic!("Test broke"),
    }
}

#[test]
fn parse_fetch_variations() {
    one_statement_parses_to(
        "SELECT foo FROM bar FETCH FIRST 10 ROW ONLY",
        "SELECT foo FROM bar FETCH FIRST 10 ROWS ONLY",
    );
    one_statement_parses_to(
        "SELECT foo FROM bar FETCH NEXT 10 ROW ONLY",
        "SELECT foo FROM bar FETCH FIRST 10 ROWS ONLY",
    );
    one_statement_parses_to(
        "SELECT foo FROM bar FETCH NEXT 10 ROWS WITH TIES",
        "SELECT foo FROM bar FETCH FIRST 10 ROWS WITH TIES",
    );
    one_statement_parses_to(
        "SELECT foo FROM bar FETCH NEXT ROWS WITH TIES",
        "SELECT foo FROM bar FETCH FIRST ROWS WITH TIES",
    );
    one_statement_parses_to(
        "SELECT foo FROM bar FETCH FIRST ROWS ONLY",
        "SELECT foo FROM bar FETCH FIRST ROWS ONLY",
    );
}

#[test]
fn lateral_derived() {
    fn chk(lateral_in: bool) {
        let lateral_str = if lateral_in { "LATERAL " } else { "" };
        let sql = format!(
            "SELECT * FROM customer LEFT JOIN {}\
             (SELECT * FROM order WHERE order.customer = customer.id LIMIT 3) AS order ON true",
            lateral_str
        );
        let select = verified_only_select(&sql);
        let from = only(select.from);
        assert_eq!(from.joins.len(), 1);
        let join = &from.joins[0];
        assert_eq!(
            join.join_operator,
            JoinOperator::LeftOuter(JoinConstraint::On(Expr::Value(Value::Boolean(true))))
        );
        if let TableFactor::Derived {
            lateral,
            ref subquery,
            alias: Some(ref alias),
        } = join.relation
        {
            assert_eq!(lateral_in, lateral);
            assert_eq!(Ident::new("order"), alias.name);
            assert_eq!(
                subquery.to_string(),
                "SELECT * FROM order WHERE order.customer = customer.id LIMIT 3"
            );
        } else {
            unreachable!()
        }
    }
    chk(false);
    chk(true);

    let sql = "SELECT * FROM customer LEFT JOIN LATERAL generate_series(1, customer.id)";
    let res = parse_sql_statements(sql);
    assert_eq!(
        ParserError::ParserError(
            "Expected subquery after LATERAL, found: generate_series".to_string()
        ),
        res.unwrap_err()
    );

    let sql = "SELECT * FROM a LEFT JOIN LATERAL (b CROSS JOIN c)";
    let res = parse_sql_statements(sql);
    assert_eq!(
        ParserError::ParserError(
            "Expected SELECT, VALUES, or a subquery in the query body, found: b".to_string()
        ),
        res.unwrap_err()
    );
}

#[test]
fn parse_start_transaction() {
    match verified_stmt("START TRANSACTION READ ONLY, READ WRITE, ISOLATION LEVEL SERIALIZABLE") {
        Statement::StartTransaction { modes } => assert_eq!(
            modes,
            vec![
                TransactionMode::AccessMode(TransactionAccessMode::ReadOnly),
                TransactionMode::AccessMode(TransactionAccessMode::ReadWrite),
                TransactionMode::IsolationLevel(TransactionIsolationLevel::Serializable),
            ]
        ),
        _ => unreachable!(),
    }

    // For historical reasons, PostgreSQL allows the commas between the modes to
    // be omitted.
    match one_statement_parses_to(
        "START TRANSACTION READ ONLY READ WRITE ISOLATION LEVEL SERIALIZABLE",
        "START TRANSACTION READ ONLY, READ WRITE, ISOLATION LEVEL SERIALIZABLE",
    ) {
        Statement::StartTransaction { modes } => assert_eq!(
            modes,
            vec![
                TransactionMode::AccessMode(TransactionAccessMode::ReadOnly),
                TransactionMode::AccessMode(TransactionAccessMode::ReadWrite),
                TransactionMode::IsolationLevel(TransactionIsolationLevel::Serializable),
            ]
        ),
        _ => unreachable!(),
    }

    verified_stmt("START TRANSACTION");
    one_statement_parses_to("BEGIN", "START TRANSACTION");
    one_statement_parses_to("BEGIN WORK", "START TRANSACTION");
    one_statement_parses_to("BEGIN TRANSACTION", "START TRANSACTION");

    verified_stmt("START TRANSACTION ISOLATION LEVEL READ UNCOMMITTED");
    verified_stmt("START TRANSACTION ISOLATION LEVEL READ COMMITTED");
    verified_stmt("START TRANSACTION ISOLATION LEVEL REPEATABLE READ");
    verified_stmt("START TRANSACTION ISOLATION LEVEL SERIALIZABLE");

    // Regression test for https://github.com/andygrove/sqlparser-rs/pull/139,
    // in which START TRANSACTION would fail to parse if followed by a statement
    // terminator.
    assert_eq!(
        parse_sql_statements("START TRANSACTION; SELECT 1"),
        Ok(vec![
            verified_stmt("START TRANSACTION"),
            verified_stmt("SELECT 1"),
        ])
    );

    let res = parse_sql_statements("START TRANSACTION ISOLATION LEVEL BAD");
    assert_eq!(
        ParserError::ParserError("Expected isolation level, found: BAD".to_string()),
        res.unwrap_err()
    );

    let res = parse_sql_statements("START TRANSACTION BAD");
    assert_eq!(
        ParserError::ParserError("Expected end of statement, found: BAD".to_string()),
        res.unwrap_err()
    );

    let res = parse_sql_statements("START TRANSACTION READ ONLY,");
    assert_eq!(
        ParserError::ParserError("Expected transaction mode, found: EOF".to_string()),
        res.unwrap_err()
    );
}

#[test]
fn parse_set_transaction() {
    // SET TRANSACTION shares transaction mode parsing code with START
    // TRANSACTION, so no need to duplicate the tests here. We just do a quick
    // sanity check.
    match verified_stmt("SET TRANSACTION READ ONLY, READ WRITE, ISOLATION LEVEL SERIALIZABLE") {
        Statement::SetTransaction { modes } => assert_eq!(
            modes,
            vec![
                TransactionMode::AccessMode(TransactionAccessMode::ReadOnly),
                TransactionMode::AccessMode(TransactionAccessMode::ReadWrite),
                TransactionMode::IsolationLevel(TransactionIsolationLevel::Serializable),
            ]
        ),
        _ => unreachable!(),
    }
}

#[test]
fn parse_commit() {
    match verified_stmt("COMMIT") {
        Statement::Commit { chain: false } => (),
        _ => unreachable!(),
    }

    match verified_stmt("COMMIT AND CHAIN") {
        Statement::Commit { chain: true } => (),
        _ => unreachable!(),
    }

    one_statement_parses_to("COMMIT AND NO CHAIN", "COMMIT");
    one_statement_parses_to("COMMIT WORK AND NO CHAIN", "COMMIT");
    one_statement_parses_to("COMMIT TRANSACTION AND NO CHAIN", "COMMIT");
    one_statement_parses_to("COMMIT WORK AND CHAIN", "COMMIT AND CHAIN");
    one_statement_parses_to("COMMIT TRANSACTION AND CHAIN", "COMMIT AND CHAIN");
    one_statement_parses_to("COMMIT WORK", "COMMIT");
    one_statement_parses_to("COMMIT TRANSACTION", "COMMIT");
}

#[test]
fn parse_rollback() {
    match verified_stmt("ROLLBACK") {
        Statement::Rollback { chain: false } => (),
        _ => unreachable!(),
    }

    match verified_stmt("ROLLBACK AND CHAIN") {
        Statement::Rollback { chain: true } => (),
        _ => unreachable!(),
    }

    one_statement_parses_to("ROLLBACK AND NO CHAIN", "ROLLBACK");
    one_statement_parses_to("ROLLBACK WORK AND NO CHAIN", "ROLLBACK");
    one_statement_parses_to("ROLLBACK TRANSACTION AND NO CHAIN", "ROLLBACK");
    one_statement_parses_to("ROLLBACK WORK AND CHAIN", "ROLLBACK AND CHAIN");
    one_statement_parses_to("ROLLBACK TRANSACTION AND CHAIN", "ROLLBACK AND CHAIN");
    one_statement_parses_to("ROLLBACK WORK", "ROLLBACK");
    one_statement_parses_to("ROLLBACK TRANSACTION", "ROLLBACK");
}

#[test]
#[should_panic(expected = "Parse results with GenericDialect are different from PostgreSqlDialect")]
fn ensure_multiple_dialects_are_tested() {
    // The SQL here must be parsed differently by different dialects.
    // At the time of writing, `@foo` is accepted as a valid identifier
    // by the Generic and the MSSQL dialect, but not by Postgres and ANSI.
    let _ = parse_sql_statements("SELECT @foo");
}

fn parse_sql_statements(sql: &str) -> Result<Vec<Statement>, ParserError> {
    all_dialects().parse_sql_statements(sql)
}

fn one_statement_parses_to(sql: &str, canonical: &str) -> Statement {
    all_dialects().one_statement_parses_to(sql, canonical)
}

fn verified_stmt(query: &str) -> Statement {
    all_dialects().verified_stmt(query)
}

fn verified_query(query: &str) -> Query {
    all_dialects().verified_query(query)
}

fn verified_only_select(query: &str) -> Select {
    all_dialects().verified_only_select(query)
}

fn verified_expr(query: &str) -> Expr {
    all_dialects().verified_expr(query)
}