fix: parse snowflake fetch clause

Author: Vedin

src/parser/mod.rs

@@ -15017,6 +15017,9 @@ impl<'a> Parser<'a> {
 
     /// Parse a FETCH clause
     pub fn parse_fetch(&mut self) -> Result<Fetch, ParserError> {
+        if dialect_of!(self is SnowflakeDialect) {
+            return self.parse_snowflake_fetch();
+        }
         self.expect_one_of_keywords(&[Keyword::FIRST, Keyword::NEXT])?;
         let (quantity, percent) = if self
             .parse_one_of_keywords(&[Keyword::ROW, Keyword::ROWS])
@@ -15043,6 +15046,22 @@ impl<'a> Parser<'a> {
         })
     }
 
+    /// Parse a FETCH clause with Snowflake-specific syntax
+    fn parse_snowflake_fetch(&mut self) -> Result<Fetch, ParserError> {
+        // Snowflake: All additional keywords are optional. WITH TIES is not allowed.
+        let _ = self.parse_one_of_keywords(&[Keyword::FIRST, Keyword::NEXT]);
+
+        let quantity = Expr::Value(self.parse_value()?);
+        let _ = self.parse_one_of_keywords(&[Keyword::ROW, Keyword::ROWS]);
+        let _ = self.parse_keyword(Keyword::ONLY);
+
+        Ok(Fetch {
+            with_ties: false,
+            percent: false,
+            quantity: Some(quantity),
+        })
+    }
+
     /// Parse a FOR UPDATE/FOR SHARE clause
     pub fn parse_lock(&mut self) -> Result<LockClause, ParserError> {
         let lock_type = match self.expect_one_of_keywords(&[Keyword::UPDATE, Keyword::SHARE])? {

tests/sqlparser_snowflake.rs

@@ -4146,3 +4146,36 @@ END
     assert_eq!(2, exception[1].idents.len());
     assert_eq!(2, exception[1].statements.len());
 }
+
+#[test]
+fn test_snowflake_fetch_clause_syntax() {
+    let canonical = "SELECT c1 FROM fetch_test FETCH FIRST 2 ROWS ONLY";
+    snowflake().verified_only_select_with_canonical("SELECT c1 FROM fetch_test FETCH 2", canonical);
+
+    snowflake()
+        .verified_only_select_with_canonical("SELECT c1 FROM fetch_test FETCH FIRST 2", canonical);
+    snowflake()
+        .verified_only_select_with_canonical("SELECT c1 FROM fetch_test FETCH NEXT 2", canonical);
+
+    snowflake()
+        .verified_only_select_with_canonical("SELECT c1 FROM fetch_test FETCH 2 ROW", canonical);
+
+    snowflake().verified_only_select_with_canonical(
+        "SELECT c1 FROM fetch_test FETCH FIRST 2 ROWS",
+        canonical,
+    );
+
+    snowflake()
+        .verified_only_select_with_canonical("SELECT c1 FROM fetch_test FETCH 2 ONLY", canonical);
+    let res = snowflake().parse_sql_statements("SELECT c1 FROM fetch_test FETCH 2 PERCENT");
+    assert_eq!(
+        res.unwrap_err().to_string(),
+        "sql parser error: Expected: end of statement, found: PERCENT"
+    );
+    let res =
+        snowflake().parse_sql_statements("SELECT c1 FROM fetch_test FETCH FIRST 2 ROWS WITH TIES");
+    assert_eq!(
+        res.unwrap_err().to_string(),
+        "sql parser error: Expected: end of statement, found: WITH"
+    );
+}