Snowflake: Support semi-structured data (#693)

* Support parse json in snowflake

* MR Review

* Lint

* Try to fix right as value

* Fix tests

* Fix lint

* Add generic dialect

* Add support in key location

Author: yuval-illumex

src/ast/mod.rs

@@ -187,6 +187,8 @@ pub enum JsonOperator {
     HashArrow,
     /// #>> Extracts JSON sub-object at the specified path as text
     HashLongArrow,
+    /// : Colon is used by Snowflake (Which is similar to LongArrow)
+    Colon,
 }
 
 impl fmt::Display for JsonOperator {
@@ -204,6 +206,9 @@ impl fmt::Display for JsonOperator {
             JsonOperator::HashLongArrow => {
                 write!(f, "#>>")
             }
+            JsonOperator::Colon => {
+                write!(f, ":")
+            }
         }
     }
 }
@@ -757,7 +762,11 @@ impl fmt::Display for Expr {
                 operator,
                 right,
             } => {
-                write!(f, "{} {} {}", left, operator, right)
+                if operator == &JsonOperator::Colon {
+                    write!(f, "{}{}{}", left, operator, right)
+                } else {
+                    write!(f, "{} {} {}", left, operator, right)
+                }
             }
             Expr::CompositeAccess { expr, key } => {
                 write!(f, "{}.{}", expr, key)

src/ast/value.rs

@@ -45,6 +45,8 @@ pub enum Value {
     Null,
     /// `?` or `$` Prepared statement arg placeholder
     Placeholder(String),
+    /// Add support of snowflake field:key - key should be a value
+    UnQuotedString(String),
 }
 
 impl fmt::Display for Value {
@@ -59,6 +61,7 @@ impl fmt::Display for Value {
             Value::Boolean(v) => write!(f, "{}", v),
             Value::Null => write!(f, "NULL"),
             Value::Placeholder(v) => write!(f, "{}", v),
+            Value::UnQuotedString(v) => write!(f, "{}", v),
         }
     }
 }

src/parser.rs

@@ -1427,6 +1427,12 @@ impl<'a> Parser<'a> {
                 return self.parse_array_index(expr);
             }
             self.parse_map_access(expr)
+        } else if Token::Colon == tok {
+            Ok(Expr::JsonAccess {
+                left: Box::new(expr),
+                operator: JsonOperator::Colon,
+                right: Box::new(Expr::Value(self.parse_value()?)),
+            })
         } else if Token::Arrow == tok
             || Token::LongArrow == tok
             || Token::HashArrow == tok
@@ -1628,6 +1634,7 @@ impl<'a> Parser<'a> {
             Token::Plus | Token::Minus => Ok(Self::PLUS_MINUS_PREC),
             Token::Mul | Token::Div | Token::Mod | Token::StringConcat => Ok(40),
             Token::DoubleColon => Ok(50),
+            Token::Colon => Ok(50),
             Token::ExclamationMark => Ok(50),
             Token::LBracket
             | Token::LongArrow
@@ -3446,6 +3453,10 @@ impl<'a> Parser<'a> {
                     Some('\'') => Ok(Value::SingleQuotedString(w.value)),
                     _ => self.expected("A value?", Token::Word(w))?,
                 },
+                // Case when Snowflake Semi-structured data like key:value
+                Keyword::NoKeyword | Keyword::LOCATION if dialect_of!(self is SnowflakeDialect | GenericDialect) => {
+                    Ok(Value::UnQuotedString(w.value))
+                }
                 _ => self.expected("a concrete value", Token::Word(w)),
             },
             // The call to n.parse() returns a bigdecimal when the

tests/sqlparser_snowflake.rs

@@ -143,6 +143,22 @@ fn test_single_table_in_parenthesis_with_alias() {
     );
 }
 
+#[test]
+fn parse_json_using_colon() {
+    let sql = "SELECT a:b FROM t";
+    let select = snowflake().verified_only_select(sql);
+    assert_eq!(
+        SelectItem::UnnamedExpr(Expr::JsonAccess {
+            left: Box::new(Expr::Identifier(Ident::new("a"))),
+            operator: JsonOperator::Colon,
+            right: Box::new(Expr::Value(Value::UnQuotedString("b".to_string()))),
+        }),
+        select.projection[0]
+    );
+
+    snowflake().one_statement_parses_to("SELECT a:b::int FROM t", "SELECT CAST(a:b AS INT) FROM t");
+}
+
 fn snowflake() -> TestedDialects {
     TestedDialects {
         dialects: vec![Box::new(SnowflakeDialect {})],