fix: parse snowflake fetch clause (apache#1894)

Author: Vedin

src/parser/mod.rs

@@ -13798,7 +13798,8 @@ impl<'a> Parser<'a> {
 
     /// Parse a FETCH clause
     pub fn parse_fetch(&mut self) -> Result<Fetch, ParserError> {
-        self.expect_one_of_keywords(&[Keyword::FIRST, Keyword::NEXT])?;
+        let _ = self.parse_one_of_keywords(&[Keyword::FIRST, Keyword::NEXT]);
+
         let (quantity, percent) = if self
             .parse_one_of_keywords(&[Keyword::ROW, Keyword::ROWS])
             .is_some()
@@ -13807,16 +13808,16 @@ impl<'a> Parser<'a> {
         } else {
             let quantity = Expr::Value(self.parse_value()?);
             let percent = self.parse_keyword(Keyword::PERCENT);
-            self.expect_one_of_keywords(&[Keyword::ROW, Keyword::ROWS])?;
+            let _ = self.parse_one_of_keywords(&[Keyword::ROW, Keyword::ROWS]);
             (Some(quantity), percent)
         };
+
         let with_ties = if self.parse_keyword(Keyword::ONLY) {
             false
-        } else if self.parse_keywords(&[Keyword::WITH, Keyword::TIES]) {
-            true
         } else {
-            return self.expected("one of ONLY or WITH TIES", self.peek_token());
+            self.parse_keywords(&[Keyword::WITH, Keyword::TIES])
         };
+
         Ok(Fetch {
             with_ties,
             percent,

tests/sqlparser_snowflake.rs

@@ -465,10 +465,12 @@ fn test_snowflake_create_table_cluster_by() {
         }
         _ => unreachable!(),
     }
-    match snowflake().verified_stmt("CREATE TABLE my_table (ts DATE, a TEXT) CLUSTER BY (to_date(ts), a)") {
+    match snowflake()
+        .verified_stmt("CREATE TABLE my_table (ts DATE, a TEXT) CLUSTER BY (to_date(ts), a)")
+    {
         Statement::CreateTable(CreateTable {
-                                   name, cluster_by, ..
-                               }) => {
+            name, cluster_by, ..
+        }) => {
             assert_eq!("my_table", name.to_string());
             assert_eq!(
                 Some(WrappedCollection::Parentheses(vec![
@@ -3527,3 +3529,22 @@ fn test_alter_session() {
     );
     snowflake().one_statement_parses_to("ALTER SESSION UNSET a\nB", "ALTER SESSION UNSET a, B");
 }
+
+#[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,
+    );
+}