snowflake: join where

Author: donhcd

src/ast/query.rs

@@ -370,6 +370,7 @@ impl fmt::Display for Join {
                 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
                     match self.0 {
                         JoinConstraint::On(expr) => write!(f, " ON {}", expr),
+                        JoinConstraint::Where(expr) => write!(f, " WHERE {}", expr),
                         JoinConstraint::Using(attrs) => {
                             write!(f, " USING({})", display_comma_separated(attrs))
                         }
@@ -433,6 +434,8 @@ pub enum JoinOperator {
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub enum JoinConstraint {
     On(Expr),
+    /// snowflake-specific: https://docs.snowflake.com/en/sql-reference/constructs/where.html#joins-in-the-where-clause
+    Where(Expr),
     Using(Vec<Ident>),
     Natural,
 }

src/parser.rs

@@ -2328,6 +2328,9 @@ impl<'a> Parser<'a> {
         } else if self.parse_keyword(Keyword::ON) {
             let constraint = self.parse_expr()?;
             Ok(JoinConstraint::On(constraint))
+        } else if dialect_of!(self is SnowflakeDialect) && self.parse_keyword(Keyword::WHERE) {
+            let constraint = self.parse_expr()?;
+            Ok(JoinConstraint::Where(constraint))
         } else if self.parse_keyword(Keyword::USING) {
             let columns = self.parse_parenthesized_column_list(Mandatory)?;
             Ok(JoinConstraint::Using(columns))