Merge pull request #65 from nickolay/pr/ddl-improvements

* Rewrite parsing of `ALTER TABLE ADD CONSTRAINT`
* Support constraints in CREATE TABLE
* Change `Value::Long()` to be unsigned, use u64 consistently
* Allow trailing comma in CREATE TABLE

Author: nickolay

src/sqlast/ddl.rs

@@ -0,0 +1,86 @@
+//! AST types specific to CREATE/ALTER variants of `SQLStatement`
+//! (commonly referred to as Data Definition Language, or DDL)
+use super::{ASTNode, SQLIdent, SQLObjectName};
+
+/// An `ALTER TABLE` (`SQLStatement::SQLAlterTable`) operation
+#[derive(Debug, Clone, PartialEq)]
+pub enum AlterTableOperation {
+    /// `ADD <table_constraint>`
+    AddConstraint(TableConstraint),
+    /// TODO: implement `DROP CONSTRAINT <name>`
+    DropConstraint { name: SQLIdent },
+}
+
+impl ToString for AlterTableOperation {
+    fn to_string(&self) -> String {
+        match self {
+            AlterTableOperation::AddConstraint(c) => format!("ADD {}", c.to_string()),
+            AlterTableOperation::DropConstraint { name } => format!("DROP CONSTRAINT {}", name),
+        }
+    }
+}
+
+/// A table-level constraint, specified in a `CREATE TABLE` or an
+/// `ALTER TABLE ADD <constraint>` statement.
+#[derive(Debug, Clone, PartialEq)]
+pub enum TableConstraint {
+    /// `[ CONSTRAINT <name> ] { PRIMARY KEY | UNIQUE } (<columns>)`
+    Unique {
+        name: Option<SQLIdent>,
+        columns: Vec<SQLIdent>,
+        /// Whether this is a `PRIMARY KEY` or just a `UNIQUE` constraint
+        is_primary: bool,
+    },
+    /// A referential integrity constraint (`[ CONSTRAINT <name> ] FOREIGN KEY (<columns>)
+    /// REFERENCES <foreign_table> (<referred_columns>)`)
+    ForeignKey {
+        name: Option<SQLIdent>,
+        columns: Vec<SQLIdent>,
+        foreign_table: SQLObjectName,
+        referred_columns: Vec<SQLIdent>,
+    },
+    /// `[ CONSTRAINT <name> ] CHECK (<expr>)`
+    Check {
+        name: Option<SQLIdent>,
+        expr: Box<ASTNode>,
+    },
+}
+
+impl ToString for TableConstraint {
+    fn to_string(&self) -> String {
+        fn format_constraint_name(name: &Option<SQLIdent>) -> String {
+            name.as_ref()
+                .map(|name| format!("CONSTRAINT {} ", name))
+                .unwrap_or_default()
+        }
+        match self {
+            TableConstraint::Unique {
+                name,
+                columns,
+                is_primary,
+            } => format!(
+                "{}{} ({})",
+                format_constraint_name(name),
+                if *is_primary { "PRIMARY KEY" } else { "UNIQUE" },
+                columns.join(", ")
+            ),
+            TableConstraint::ForeignKey {
+                name,
+                columns,
+                foreign_table,
+                referred_columns,
+            } => format!(
+                "{}FOREIGN KEY ({}) REFERENCES {}({})",
+                format_constraint_name(name),
+                columns.join(", "),
+                foreign_table.to_string(),
+                referred_columns.join(", ")
+            ),
+            TableConstraint::Check { name, expr } => format!(
+                "{}CHECK ({})",
+                format_constraint_name(name),
+                expr.to_string()
+            ),
+        }
+    }
+}

src/sqlast/mod.rs

@@ -14,18 +14,18 @@
 
 //! SQL Abstract Syntax Tree (AST) types
 
+mod ddl;
 mod query;
 mod sql_operator;
 mod sqltype;
-mod table_key;
 mod value;
 
+pub use self::ddl::{AlterTableOperation, TableConstraint};
 pub use self::query::{
     Cte, Fetch, Join, JoinConstraint, JoinOperator, SQLOrderByExpr, SQLQuery, SQLSelect,
     SQLSelectItem, SQLSetExpr, SQLSetOperator, TableFactor,
 };
 pub use self::sqltype::SQLType;
-pub use self::table_key::{AlterOperation, Key, TableKey};
 pub use self::value::Value;
 
 pub use self::sql_operator::SQLOperator;
@@ -396,6 +396,7 @@ pub enum SQLStatement {
         name: SQLObjectName,
         /// Optional schema
         columns: Vec<SQLColumnDef>,
+        constraints: Vec<TableConstraint>,
         external: bool,
         file_format: Option<FileFormat>,
         location: Option<String>,
@@ -404,7 +405,7 @@ pub enum SQLStatement {
     SQLAlterTable {
         /// Table name
         name: SQLObjectName,
-        operation: AlterOperation,
+        operation: AlterTableOperation,
     },
     /// DROP TABLE
     SQLDrop {
@@ -503,21 +504,30 @@ impl ToString for SQLStatement {
             SQLStatement::SQLCreateTable {
                 name,
                 columns,
+                constraints,
                 external,
                 file_format,
                 location,
-            } if *external => format!(
-                "CREATE EXTERNAL TABLE {} ({}) STORED AS {} LOCATION '{}'",
-                name.to_string(),
-                comma_separated_string(columns),
-                file_format.as_ref().unwrap().to_string(),
-                location.as_ref().unwrap()
-            ),
-            SQLStatement::SQLCreateTable { name, columns, .. } => format!(
-                "CREATE TABLE {} ({})",
-                name.to_string(),
-                comma_separated_string(columns)
-            ),
+            } => {
+                let mut s = format!(
+                    "CREATE {}TABLE {} ({}",
+                    if *external { "EXTERNAL " } else { "" },
+                    name.to_string(),
+                    comma_separated_string(columns)
+                );
+                if !constraints.is_empty() {
+                    s += &format!(", {}", comma_separated_string(constraints));
+                }
+                s += ")";
+                if *external {
+                    s += &format!(
+                        " STORED AS {} LOCATION '{}'",
+                        file_format.as_ref().unwrap().to_string(),
+                        location.as_ref().unwrap()
+                    );
+                }
+                s
+            }
             SQLStatement::SQLAlterTable { name, operation } => {
                 format!("ALTER TABLE {} {}", name.to_string(), operation.to_string())
             }

src/sqlast/sqltype.rs

@@ -1,26 +1,26 @@
 use super::SQLObjectName;
 
-/// SQL datatypes for literals in SQL statements
+/// SQL data types
 #[derive(Debug, Clone, PartialEq)]
 pub enum SQLType {
     /// Fixed-length character type e.g. CHAR(10)
-    Char(Option<usize>),
+    Char(Option<u64>),
     /// Variable-length character type e.g. VARCHAR(10)
-    Varchar(Option<usize>),
+    Varchar(Option<u64>),
     /// Uuid type
     Uuid,
     /// Large character object e.g. CLOB(1000)
-    Clob(usize),
+    Clob(u64),
     /// Fixed-length binary type e.g. BINARY(10)
-    Binary(usize),
+    Binary(u64),
     /// Variable-length binary type e.g. VARBINARY(10)
-    Varbinary(usize),
+    Varbinary(u64),
     /// Large binary object e.g. BLOB(1000)
-    Blob(usize),
+    Blob(u64),
     /// Decimal type with optional precision and scale e.g. DECIMAL(10,2)
-    Decimal(Option<usize>, Option<usize>),
+    Decimal(Option<u64>, Option<u64>),
     /// Floating point with optional precision e.g. FLOAT(8)
-    Float(Option<usize>),
+    Float(Option<u64>),
     /// Small integer
     SmallInt,
     /// Integer
@@ -87,7 +87,7 @@ impl ToString for SQLType {
     }
 }
 
-fn format_type_with_optional_length(sql_type: &str, len: &Option<usize>) -> String {
+fn format_type_with_optional_length(sql_type: &str, len: &Option<u64>) -> String {
     let mut s = sql_type.to_string();
     if let Some(len) = len {
         s += &format!("({})", len);

src/sqlast/table_key.rs

@@ -1,15 +1,15 @@
-/// SQL values such as int, double, string, timestamp
+/// Primitive SQL values such as number and string
 #[derive(Debug, Clone, PartialEq)]
 pub enum Value {
-    /// Literal signed long
-    Long(i64),
-    /// Literal floating point value
+    /// Unsigned integer value
+    Long(u64),
+    /// Unsigned floating point value
     Double(f64),
     /// 'string value'
     SingleQuotedString(String),
     /// N'string value'
     NationalStringLiteral(String),
-    /// Boolean value true or false,
+    /// Boolean value true or false
     Boolean(bool),
     /// NULL value in insert statements,
     Null,