diff --git a/src/parser/mod.rs b/src/parser/mod.rs index d00f28a55..0f1c80941 100644 --- a/src/parser/mod.rs +++ b/src/parser/mod.rs @@ -1474,6 +1474,11 @@ impl<'a> Parser<'a> { let result = self.parse_comma_separated(|p| p.parse_tuple(true, true))?; self.expect_token(&Token::RParen)?; Ok(Expr::Rollup(result)) + } else if self.consume_tokens(&[Token::LParen, Token::RParen]) { + // PostgreSQL allow to use empty tuple as a group by expression, + // e.g. `GROUP BY (), name`. Please refer to GROUP BY Clause section in + // [PostgreSQL](https://www.postgresql.org/docs/16/sql-select.html) + Ok(Expr::Tuple(vec![])) } else { self.parse_expr() } diff --git a/tests/sqlparser_common.rs b/tests/sqlparser_common.rs index 1adda149e..25177c38b 100644 --- a/tests/sqlparser_common.rs +++ b/tests/sqlparser_common.rs @@ -42,6 +42,7 @@ mod test_utils; #[cfg(test)] use pretty_assertions::assert_eq; +use sqlparser::ast::Expr::Identifier; use sqlparser::test_utils::all_dialects_except; #[test] @@ -10131,3 +10132,30 @@ fn parse_auto_increment_too_large() { assert!(res.is_err(), "{res:?}"); } + +#[test] +fn test_group_by_nothing() { + let Select { group_by, .. } = all_dialects_where(|d| d.supports_group_by_expr()) + .verified_only_select("SELECT count(1) FROM t GROUP BY ()"); + { + std::assert_eq!( + GroupByExpr::Expressions(vec![Expr::Tuple(vec![])], vec![]), + group_by + ); + } + + let Select { group_by, .. } = all_dialects_where(|d| d.supports_group_by_expr()) + .verified_only_select("SELECT name, count(1) FROM t GROUP BY name, ()"); + { + std::assert_eq!( + GroupByExpr::Expressions( + vec![ + Identifier(Ident::new("name".to_string())), + Expr::Tuple(vec![]) + ], + vec![] + ), + group_by + ); + } +}