Merge pull request apache#8 from zhyass/main

Add tuple expression

Author: sundy-li

src/ast/mod.rs

@@ -244,6 +244,8 @@ pub enum Expr {
     },
     /// Nested expression e.g. `(foo > bar)` or `(1)`
     Nested(Box<Expr>),
+    // Tuple expression e.g. `(foo,bar)`
+    Tuple(Vec<Expr>),
     /// A literal value, such as string, number, date or NULL
     Value(Value),
     /// A constant of form `<data_type> 'value'`.
@@ -348,6 +350,7 @@ impl fmt::Display for Expr {
             Expr::Extract { field, expr } => write!(f, "EXTRACT({} FROM {})", field, expr),
             Expr::Collate { expr, collation } => write!(f, "{} COLLATE {}", expr, collation),
             Expr::Nested(ast) => write!(f, "({})", ast),
+            Expr::Tuple(ast) => write!(f, "({})", display_comma_separated(ast)),
             Expr::Value(v) => write!(f, "{}", v),
             Expr::TypedString { data_type, value } => {
                 write!(f, "{}", data_type)?;

src/parser.rs

@@ -447,7 +447,12 @@ impl<'a> Parser<'a> {
                         self.prev_token();
                         Expr::Subquery(Box::new(self.parse_query()?))
                     } else {
-                        Expr::Nested(Box::new(self.parse_expr()?))
+                        let exprs = self.parse_comma_separated(Parser::parse_expr)?;
+                        if exprs.len() == 1 {
+                            Expr::Nested(Box::new(exprs[0].clone()))
+                        } else {
+                            Expr::Tuple(exprs)
+                        }
                     };
                 self.expect_token(&Token::RParen)?;
                 Ok(expr)

tests/sqlparser_common.rs

@@ -2359,6 +2359,27 @@ fn parse_parens() {
     );
 }
 
+#[test]
+fn parse_tuples() {
+    use self::BinaryOperator::*;
+    use self::Expr::*;
+    let sql = "(a, b) = (c, d)";
+    assert_eq!(
+        BinaryOp {
+            left: Box::new(Tuple(vec![
+                Identifier(Ident::new("a")),
+                Identifier(Ident::new("b")),
+            ])),
+            op: Eq,
+            right: Box::new(Tuple(vec![
+                Identifier(Ident::new("c")),
+                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";