diff --git a/session_insert.go b/session_insert.go
index c943ae11..44cae7c4 100644
--- a/session_insert.go
+++ b/session_insert.go
@@ -7,7 +7,6 @@ package xorm
 import (
 	"errors"
 	"fmt"
-	"io"
 	"reflect"
 	"sort"
 	"strconv"
@@ -355,22 +354,22 @@ func (session *Session) innerInsert(bean interface{}) (int64, error) {
 	}
 
 	var buf = builder.NewWriter()
-	if _, err := io.WriteString(buf, fmt.Sprintf("INSERT INTO %s", session.engine.Quote(tableName))); err != nil {
+	if _, err := buf.WriteString(fmt.Sprintf("INSERT INTO %s", session.engine.Quote(tableName))); err != nil {
 		return 0, err
 	}
 
 	if len(colPlaces) <= 0 {
 		if session.engine.dialect.DBType() == core.MYSQL {
-			if _, err := io.WriteString(buf, " VALUES ()"); err != nil {
+			if _, err := buf.WriteString(" VALUES ()"); err != nil {
 				return 0, err
 			}
 		} else {
-			if _, err := io.WriteString(buf, fmt.Sprintf("%s DEFAULT VALUES", output)); err != nil {
+			if _, err := buf.WriteString(fmt.Sprintf("%s DEFAULT VALUES", output)); err != nil {
 				return 0, err
 			}
 		}
 	} else {
-		if _, err := io.WriteString(buf, " ("); err != nil {
+		if _, err := buf.WriteString(" ("); err != nil {
 			return 0, err
 		}
 
@@ -379,9 +378,7 @@ func (session *Session) innerInsert(bean interface{}) (int64, error) {
 		}
 
 		if session.statement.cond.IsValid() {
-			if _, err := io.WriteString(buf, fmt.Sprintf(")%s SELECT ",
-				output,
-			)); err != nil {
+			if _, err := buf.WriteString(fmt.Sprintf(")%s SELECT ", output)); err != nil {
 				return 0, err
 			}
 
@@ -398,7 +395,7 @@ func (session *Session) innerInsert(bean interface{}) (int64, error) {
 				return 0, err
 			}
 
-			if _, err := io.WriteString(buf, fmt.Sprintf(" FROM %v WHERE ", session.engine.Quote(tableName))); err != nil {
+			if _, err := buf.WriteString(fmt.Sprintf(" FROM %v WHERE ", session.engine.Quote(tableName))); err != nil {
 				return 0, err
 			}
 
@@ -408,7 +405,7 @@ func (session *Session) innerInsert(bean interface{}) (int64, error) {
 		} else {
 			buf.Append(args...)
 
-			if _, err := io.WriteString(buf, fmt.Sprintf(")%s VALUES (%v",
+			if _, err := buf.WriteString(fmt.Sprintf(")%s VALUES (%v",
 				output,
 				colPlaces)); err != nil {
 				return 0, err
@@ -418,21 +415,21 @@ func (session *Session) innerInsert(bean interface{}) (int64, error) {
 				return 0, err
 			}
 
-			if _, err := io.WriteString(buf, ")"); err != nil {
+			if _, err := buf.WriteString(")"); err != nil {
 				return 0, err
 			}
 		}
 	}
 
-	sqlStr := buf.String()
-	args = buf.Args()
-
 	if len(table.AutoIncrement) > 0 && session.engine.dialect.DBType() == core.POSTGRES {
-		if _, err := io.WriteString(buf, " RETURNING "+session.engine.Quote(table.AutoIncrement)); err != nil {
+		if _, err := buf.WriteString(" RETURNING " + session.engine.Quote(table.AutoIncrement)); err != nil {
 			return 0, err
 		}
 	}
 
+	sqlStr := buf.String()
+	args = buf.Args()
+
 	handleAfterInsertProcessorFunc := func(bean interface{}) {
 		if session.isAutoCommit {
 			for _, closure := range session.afterClosures {
diff --git a/statement_args.go b/statement_args.go
index aec12240..c6168db1 100644
--- a/statement_args.go
+++ b/statement_args.go
@@ -6,7 +6,6 @@ package xorm
 
 import (
 	"fmt"
-	"io"
 
 	"xorm.io/builder"
 )
@@ -47,20 +46,20 @@ func writeArgs(w *builder.BytesWriter, args []interface{}) error {
 func writeStrings(w *builder.BytesWriter, cols []string, leftQuote, rightQuote string) error {
 	for i, colName := range cols {
 		if len(leftQuote) > 0 && colName[0] != '`' {
-			if _, err := io.WriteString(w, leftQuote); err != nil {
+			if _, err := w.WriteString(leftQuote); err != nil {
 				return err
 			}
 		}
-		if _, err := io.WriteString(w, colName); err != nil {
+		if _, err := w.WriteString(colName); err != nil {
 			return err
 		}
 		if len(rightQuote) > 0 && colName[len(colName)-1] != '`' {
-			if _, err := io.WriteString(w, rightQuote); err != nil {
+			if _, err := w.WriteString(rightQuote); err != nil {
 				return err
 			}
 		}
 		if i+1 != len(cols) {
-			if _, err := io.WriteString(w, ","); err != nil {
+			if _, err := w.WriteString(","); err != nil {
 				return err
 			}
 		}
diff --git a/statement_exprparam.go b/statement_exprparam.go
index dfe3730c..a72f0aea 100644
--- a/statement_exprparam.go
+++ b/statement_exprparam.go
@@ -6,7 +6,6 @@ package xorm
 
 import (
 	"fmt"
-	"io"
 	"strings"
 
 	"xorm.io/builder"
@@ -57,7 +56,7 @@ func (exprs *exprParams) getByName(colName string) (exprParam, bool) {
 	return exprParam{}, false
 }
 
-func (exprs *exprParams) writeArgs(w builder.Writer) error {
+func (exprs *exprParams) writeArgs(w *builder.BytesWriter) error {
 	for _, expr := range exprs.args {
 		switch arg := expr.(type) {
 		case *builder.Builder:
@@ -65,7 +64,7 @@ func (exprs *exprParams) writeArgs(w builder.Writer) error {
 				return err
 			}
 		default:
-			if _, err := io.WriteString(w, fmt.Sprintf("%v", arg)); err != nil {
+			if _, err := w.WriteString(fmt.Sprintf("%v", arg)); err != nil {
 				return err
 			}
 		}
@@ -73,12 +72,12 @@ func (exprs *exprParams) writeArgs(w builder.Writer) error {
 	return nil
 }
 
-func (exprs *exprParams) writeNameArgs(w builder.Writer) error {
+func (exprs *exprParams) writeNameArgs(w *builder.BytesWriter) error {
 	for i, colName := range exprs.colNames {
-		if _, err := io.WriteString(w, colName); err != nil {
+		if _, err := w.WriteString(colName); err != nil {
 			return err
 		}
-		if _, err := io.WriteString(w, "="); err != nil {
+		if _, err := w.WriteString("="); err != nil {
 			return err
 		}
 
@@ -92,7 +91,7 @@ func (exprs *exprParams) writeNameArgs(w builder.Writer) error {
 		}
 
 		if i+1 != len(exprs.colNames) {
-			if _, err := io.WriteString(w, ","); err != nil {
+			if _, err := w.WriteString(","); err != nil {
 				return err
 			}
 		}