support create table like statement

go/vt/sqlparser/ast.go

@@ -682,6 +682,7 @@ type DDL struct {
 	NewName       TableName
 	IfExists      bool
 	TableSpec     *TableSpec
+	OptLike       *OptLike
 	PartitionSpec *PartitionSpec
 	VindexSpec    *VindexSpec
 	VindexCols    []ColIdent
@@ -706,10 +707,12 @@ const (
 func (node *DDL) Format(buf *TrackedBuffer) {
 	switch node.Action {
 	case CreateStr:
-		if node.TableSpec == nil {
-			buf.Myprintf("%s table %v", node.Action, node.NewName)
-		} else {
+		if node.OptLike != nil {
+			buf.Myprintf("%s table %v %v", node.Action, node.NewName, node.OptLike)
+		} else if node.TableSpec != nil {
 			buf.Myprintf("%s table %v %v", node.Action, node.NewName, node.TableSpec)
+		} else {
+			buf.Myprintf("%s table %v", node.Action, node.NewName)
 		}
 	case DropStr:
 		exists := ""
@@ -763,6 +766,23 @@ const (
 	ReorganizeStr = "reorganize partition"
 )
 
+// OptLike works for create table xxx like xxx
+type OptLike struct {
+	LikeTable TableName
+}
+
+// Format formats the node.
+func (node *OptLike) Format(buf *TrackedBuffer) {
+	buf.Myprintf("like %v", node.LikeTable)
+}
+
+func (node *OptLike) walkSubtree(visit Visit) error {
+	if node == nil {
+		return nil
+	}
+	return Walk(visit, node.LikeTable)
+}
+
 // PartitionSpec describe partition actions (for alter and create)
 type PartitionSpec struct {
 	Action      string

go/vt/sqlparser/parse_test.go

@@ -1945,6 +1945,37 @@ func TestCreateTable(t *testing.T) {
 	}
 }
 
+func TestCreateTableLike(t *testing.T) {
+	normal := "create table a like b"
+	testCases := []struct {
+		input  string
+		output string
+	}{
+		{
+			"create table a like b",
+			normal,
+		},
+		{
+			"create table a (like b)",
+			normal,
+		},
+		{
+			"create table ks.a like unsharded_ks.b",
+			"create table ks.a like unsharded_ks.b",
+		},
+	}
+	for _, tcase := range testCases {
+		tree, err := ParseStrictDDL(tcase.input)
+		if err != nil {
+			t.Errorf("input: %s, err: %v", tcase.input, err)
+			continue
+		}
+		if got, want := String(tree.(*DDL)), tcase.output; got != want {
+			t.Errorf("Parse(%s):\n%s, want\n%s", tcase.input, got, want)
+		}
+	}
+}
+
 func TestCreateTableEscaped(t *testing.T) {
 	testCases := []struct {
 		input  string