revert changes for fetch and add test cases for limit

e2e_test/batch/order/negative_offset.slt.part

@@ -15,6 +15,34 @@ SELECT * FROM generate_series(0,10,1) LIMIT -3;
 statement error
 SELECT * FROM generate_series(0,10,1) LIMIT -1%;
 
+statement ok
+SELECT * FROM generate_series(0,10,1) as t(v) order by v limit 1+2;
+----
+0
+1
+2
+
+
+statement ok
+SELECT * FROM generate_series(0,10,1) as t(v) order by v limit 1.5*2;
+---
+0
+1
+2
+
+
+statement ok
+SELECT * FROM generate_series(0,10,1) as t(v) order by v limit -3+4;
+---
+0
+
+statement ok
+SELECT * FROM generate_series(0,10,1) as t(v) order by v limit 1.5*2 OFFSET 2;
+---
+2
+3
+4
+
 statement ok
 CREATE TABLE integers(k int);
 

src/frontend/src/binder/query.rs

@@ -174,7 +174,7 @@ impl Binder {
             ) => {
                 with_ties = fetch_with_ties;
                 match quantity {
-                    Some(v) => Some(v),
+                    Some(v) => Some(Expr::Value(Value::Number(v))),
                     None => Some(Expr::Value(Value::Number("1".to_owned()))),
                 }
             }

src/sqlparser/src/ast/query.rs

@@ -655,7 +655,7 @@ impl fmt::Display for OrderByExpr {
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct Fetch {
     pub with_ties: bool,
-    pub quantity: Option<Expr>,
+    pub quantity: Option<String>,
 }
 
 impl fmt::Display for Fetch {

src/sqlparser/src/parser.rs

@@ -5362,7 +5362,7 @@ impl Parser<'_> {
         {
             None
         } else {
-            let quantity = self.parse_expr()?;
+            let quantity = self.parse_number_value()?;
             self.expect_one_of_keywords(&[Keyword::ROW, Keyword::ROWS])?;
             Some(quantity)
         };

src/sqlparser/tests/sqlparser_common.rs

@@ -3551,7 +3551,7 @@ fn parse_fetch() {
     let fetch_first_two_rows_only = Some(Fetch {
         with_ties: false,
 
-        quantity: Some(Expr::Value(Value::Number("2".to_owned()))),
+        quantity: Some("2".to_owned()),
     });
     let ast = verified_query("SELECT foo FROM bar FETCH FIRST 2 ROWS ONLY");
     assert_eq!(ast.fetch, fetch_first_two_rows_only);
@@ -3576,7 +3576,7 @@ fn parse_fetch() {
         ast.fetch,
         Some(Fetch {
             with_ties: true,
-            quantity: Some(Expr::Value(Value::Number("2".to_owned()))),
+            quantity: Some("2".to_owned()),
         })
     );
     let ast = verified_query(