address comments and remove typed struct flag

src/ast/mod.rs

@@ -857,12 +857,14 @@ pub enum Expr {
     /// Syntax:
     /// ```sql
     /// STRUCT<[field_name] field_type, ...>( expr1 [, ... ])
+    ///
+    /// [BigQuery](https://cloud.google.com/bigquery/docs/reference/standard-sql/data-types#struct_type)
+    /// [Databricks](https://docs.databricks.com/en/sql/language-manual/functions/struct.html)
     /// ```
     Struct {
         /// Struct values.
         values: Vec<Expr>,
-        /// BigQuery specific: Struct field definitions.
-        /// see https://cloud.google.com/bigquery/docs/reference/standard-sql/data-types#struct_type
+        /// Struct field definitions.
         fields: Vec<StructField>,
     },
     /// `BigQuery` specific: An named expression in a typeless struct [1]

src/dialect/bigquery.rs

@@ -77,9 +77,4 @@ impl Dialect for BigQueryDialect {
     fn supports_struct_literal(&self) -> bool {
         true
     }
-
-    // See https://cloud.google.com/bigquery/docs/reference/standard-sql/data-types#typed_struct_syntax
-    fn supports_typed_struct_syntax(&self) -> bool {
-        true
-    }
 }

src/dialect/generic.rs

@@ -127,8 +127,4 @@ impl Dialect for GenericDialect {
     fn supports_struct_literal(&self) -> bool {
         true
     }
-
-    fn supports_typed_struct_syntax(&self) -> bool {
-        true
-    }
 }

src/dialect/mod.rs

@@ -375,16 +375,6 @@ pub trait Dialect: Debug + Any {
         false
     }
 
-    /// Return true if the dialect supports typed struct syntax
-    ///
-    /// Example for bigquery
-    /// ```sql
-    /// SELECT STRUCT<x int64, y string>(1, 'foo')
-    /// ```
-    fn supports_typed_struct_syntax(&self) -> bool {
-        false
-    }
-
     /// Dialect-specific infix parser override
     ///
     /// This method is called to parse the next infix expression.

src/parser/mod.rs

@@ -2370,25 +2370,21 @@ impl<'a> Parser<'a> {
 
     /// Syntax
     /// ```sql
-    /// -- typed, specific to bigquery
+    /// -- typed
     /// STRUCT<[field_name] field_type, ...>( expr1 [, ... ])
     /// -- typeless
     /// STRUCT( expr1 [AS field_name] [, ... ])
     /// ```
     fn parse_struct_literal(&mut self) -> Result<Expr, ParserError> {
-        let mut fields = vec![];
-        // Typed struct syntax is only supported by BigQuery
-        // https://cloud.google.com/bigquery/docs/reference/standard-sql/data-types#typed_struct_syntax
-        if self.dialect.supports_typed_struct_syntax() {
-            self.prev_token();
-            let trailing_bracket;
-            (fields, trailing_bracket) =
-                self.parse_struct_type_def(Self::parse_struct_field_def)?;
-            if trailing_bracket.0 {
-                return parser_err!("unmatched > in STRUCT literal", self.peek_token().location);
-            }
+        // Parse the fields definition if exist `<[field_name] field_type, ...>`
+        self.prev_token();
+        let (fields, trailing_bracket) =
+            self.parse_struct_type_def(Self::parse_struct_field_def)?;
+        if trailing_bracket.0 {
+            return parser_err!("unmatched > in STRUCT literal", self.peek_token().location);
         }
 
+        // Parse the struct values `(expr1 [, ... ])`
         self.expect_token(&Token::LParen)?;
         let values = self
             .parse_comma_separated(|parser| parser.parse_struct_field_expr(!fields.is_empty()))?;

tests/sqlparser_databricks.rs

@@ -282,7 +282,7 @@ fn parse_use() {
 #[test]
 fn parse_databricks_struct_function() {
     assert_eq!(
-        databricks()
+        databricks_and_generic()
             .verified_only_select("SELECT STRUCT(1, 'foo')")
             .projection[0],
         SelectItem::UnnamedExpr(Expr::Struct {
@@ -294,7 +294,7 @@ fn parse_databricks_struct_function() {
         })
     );
     assert_eq!(
-        databricks()
+        databricks_and_generic()
             .verified_only_select("SELECT STRUCT(1 AS one, 'foo' AS foo, false)")
             .projection[0],
         SelectItem::UnnamedExpr(Expr::Struct {
@@ -313,13 +313,3 @@ fn parse_databricks_struct_function() {
         })
     );
 }
-
-#[test]
-fn parse_invalid_struct_function() {
-    assert_eq!(
-        databricks()
-            .parse_sql_statements("SELECT STRUCT<INT64>(1)") // This works only in BigQuery
-            .unwrap_err(),
-        ParserError::ParserError("Expected: (, found: <".to_string())
-    );
-}