fix: mismatch in column count and value count (#14417)

Signed-off-by: Prakhar Gurunani <[email protected]>

go/vt/vtgate/planbuilder/operators/insert.go

@@ -641,6 +641,9 @@ func modifyForAutoinc(ctx *plancontext.PlanningContext, ins *sqlparser.Insert, v
 	case sqlparser.Values:
 		autoIncValues := make(sqlparser.ValTuple, 0, len(rows))
 		for rowNum, row := range rows {
+			if len(ins.Columns) != len(row) {
+				return nil, vterrors.VT03006()
+			}
 			// Support the DEFAULT keyword by treating it as null
 			if _, ok := row[colNum].(*sqlparser.Default); ok {
 				row[colNum] = &sqlparser.NullVal{}

go/vt/vtgate/planbuilder/testdata/dml_cases.json

@@ -4889,5 +4889,15 @@
     "comment": "Unsupported update statement with a replica target destination",
     "query": "update `user[-]@replica`.user_metadata set id=2",
     "plan": "VT09002: update statement with a replica target"
+  },
+  {
+    "comment": "insert row values smaller than number of columns",
+    "query": "insert into user(one, two, three, four) values (1, 2, 3)",
+    "plan": "VT03006: column count does not match value count at row 1"
+  },
+  {
+    "comment": "insert row values greater than number of columns",
+    "query": "insert into user(one, two, three) values (1, 2, 3, 4)",
+    "plan": "VT03006: column count does not match value count at row 1"
   }
 ]