diff --git a/dialect/dialect.go b/dialect/dialect.go
index 4120985e..f21e1876 100644
--- a/dialect/dialect.go
+++ b/dialect/dialect.go
@@ -1,7 +1,7 @@
 package dialect
 
 type Dialect interface {
-	BinVar() string
+	BinVar(i int) string
 	SupportLastInsertId() bool
 	SqlTag(column interface{}, size int) string
 	PrimaryKeyTag(column interface{}, size int) string
diff --git a/dialect/mysql.go b/dialect/mysql.go
index f9e05170..0e71612b 100644
--- a/dialect/mysql.go
+++ b/dialect/mysql.go
@@ -8,7 +8,7 @@ import (
 
 type mysql struct{}
 
-func (s *mysql) BinVar() string {
+func (s *mysql) BinVar(i int) string {
 	return "?"
 }
 
diff --git a/dialect/postgres.go b/dialect/postgres.go
index 833a4a09..13a0afa0 100644
--- a/dialect/postgres.go
+++ b/dialect/postgres.go
@@ -9,8 +9,8 @@ import (
 type postgres struct {
 }
 
-func (s *postgres) BinVar() string {
-	return "$%v"
+func (s *postgres) BinVar(i int) string {
+	return fmt.Sprintf("$%v", i)
 }
 
 func (s *postgres) SupportLastInsertId() bool {
diff --git a/dialect/sqlite3.go b/dialect/sqlite3.go
index c6731b6d..f413bd14 100644
--- a/dialect/sqlite3.go
+++ b/dialect/sqlite3.go
@@ -8,7 +8,7 @@ import (
 
 type sqlite3 struct{}
 
-func (s *sqlite3) BinVar() string {
+func (s *sqlite3) BinVar(i int) string {
 	return "?"
 }
 
diff --git a/do.go b/do.go
index 8a7a3aab..db2974f4 100644
--- a/do.go
+++ b/do.go
@@ -58,7 +58,7 @@ func (s *Do) setModel(value interface{}) *Do {
 
 func (s *Do) addToVars(value interface{}) string {
 	s.sqlVars = append(s.sqlVars, value)
-	return fmt.Sprintf(s.dialect().BinVar(), len(s.sqlVars))
+	return s.dialect().BinVar(len(s.sqlVars))
 }
 
 func (s *Do) trace(t time.Time) {
diff --git a/gorm_test.go b/gorm_test.go
index 945c697f..e3ce416a 100644
--- a/gorm_test.go
+++ b/gorm_test.go
@@ -96,8 +96,7 @@ func init() {
 
 	db.SetPool(10)
 
-	err = db.DropTable(&User{}).Error
-	if err != nil {
+	if err := db.DropTable(&User{}).Error; err != nil {
 		fmt.Printf("Got error when try to delete table users, %+v\n", err)
 	}
 
diff --git a/utils.go b/utils.go
index 7586b89c..d4897c13 100644
--- a/utils.go
+++ b/utils.go
@@ -3,7 +3,6 @@ package gorm
 import (
 	"bytes"
 	"database/sql"
-	"fmt"
 
 	"reflect"
 	"strconv"
@@ -98,8 +97,3 @@ func isBlank(value reflect.Value) bool {
 	}
 	return false
 }
-
-func debug(values ...interface{}) {
-	fmt.Println("*****************")
-	fmt.Println(values)
-}