diff --git a/chain.go b/chain.go
index 3ddeb8a..8bc4367 100644
--- a/chain.go
+++ b/chain.go
@@ -291,6 +291,7 @@ func (this *Query) BuildSelectSql() (map[string]interface{}, error) {
 	withSql := ""
 	if len(this.with) > 0 {
 		var builder strings.Builder
+		builder.Reset()
 		builder.WriteString("WITH ")
 		boo := false
 		for k, v := range this.with {
@@ -351,6 +352,7 @@ func (this *Query) BuildSelectSql() (map[string]interface{}, error) {
 
 	if len(this.join) > 0 {
 		var builder strings.Builder
+		builder.Reset()
 		for _, joinitem := range this.join {
 			if len(joinitem) < 2 {
 				continue
diff --git a/db.go b/db.go
index 43c7340..32d6c77 100644
--- a/db.go
+++ b/db.go
@@ -307,6 +307,7 @@ func GetRow(dbName, table_name, alias string, titles string, with, join [][]stri
 	withSql := ""
 	if len(with) > 0 {
 		var builder strings.Builder
+		builder.Reset()
 		builder.WriteString("WITH ")
 		boo := false
 		for k, v := range with {
@@ -353,6 +354,7 @@ func GetRow(dbName, table_name, alias string, titles string, with, join [][]stri
 
 	if len(join) > 0 {
 		var builder strings.Builder
+		builder.Reset()
 		for _, joinitem := range join {
 			if len(joinitem) < 2 {
 				continue
@@ -496,6 +498,7 @@ func FetchRows(dbName, table_name, alias string, titles string, with, join [][]s
 	withSql := ""
 	if len(with) > 0 {
 		var builder strings.Builder
+		builder.Reset()
 		builder.WriteString("WITH ")
 		boo := false
 		for k, v := range with {
@@ -543,6 +546,7 @@ func FetchRows(dbName, table_name, alias string, titles string, with, join [][]s
 
 	if len(join) > 0 {
 		var builder strings.Builder
+		builder.Reset()
 		for _, joinitem := range join {
 			if len(joinitem) < 2 {
 				continue
diff --git a/transaction_chain.go b/transaction_chain.go
index d73b639..9686a04 100644
--- a/transaction_chain.go
+++ b/transaction_chain.go
@@ -225,6 +225,7 @@ func (this *TxQuery) BuildSelectSql() (map[string]interface{}, error) {
 	withSql := ""
 	if len(this.with) > 0 {
 		var builder strings.Builder
+		builder.Reset()
 		builder.WriteString("WITH ")
 		boo := false
 		for k, v := range this.with {
@@ -269,6 +270,7 @@ func (this *TxQuery) BuildSelectSql() (map[string]interface{}, error) {
 
 	if len(this.join) > 0 {
 		var builder strings.Builder
+		builder.Reset()
 		for _, joinitem := range this.join {
 			if len(joinitem) < 2 {
 				continue