diff --git a/search.go b/search.go
index db32bd11..84de4a40 100644
--- a/search.go
+++ b/search.go
@@ -1,5 +1,7 @@
 package gorm
 
+import "strconv"
+
 type search struct {
 	conditions         map[string][]interface{}
 	orders             []string
@@ -10,31 +12,31 @@ type search struct {
 	unscope            bool
 }
 
-func (s search) addToCondition(typ string, value interface{}) {
+func (s *search) addToCondition(typ string, value interface{}) {
 	s.conditions[typ] = append(s.conditions[typ], value)
 }
 
-func (s search) where(query string, values ...interface{}) {
+func (s *search) where(query string, values ...interface{}) {
 	s.addToCondition("where", map[string]interface{}{"query": query, "args": values})
 }
 
-func (s search) not(query string, values ...interface{}) {
+func (s *search) not(query string, values ...interface{}) {
 	s.addToCondition("not", map[string]interface{}{"query": query, "args": values})
 }
 
-func (s search) or(query string, values ...interface{}) {
+func (s *search) or(query string, values ...interface{}) {
 	s.addToCondition("or", map[string]interface{}{"query": query, "args": values})
 }
 
-func (s search) attrs(attrs ...interface{}) {
+func (s *search) attrs(attrs ...interface{}) {
 	s.addToCondition("attrs", toSearchableMap(attrs...))
 }
 
-func (s search) assign(attrs ...interface{}) {
+func (s *search) assign(attrs ...interface{}) {
 	s.addToCondition("assign", toSearchableMap(attrs...))
 }
 
-func (s search) order(value string, reorder ...bool) {
+func (s *search) order(value string, reorder ...bool) {
 	if len(reorder) > 0 && reorder[0] {
 		s.orders = []string{value}
 	} else {
@@ -42,24 +44,40 @@ func (s search) order(value string, reorder ...bool) {
 	}
 }
 
-func (s search) selects(value interface{}) {
+func (s *search) selects(value interface{}) {
 	if str, err := getInterfaceAsString(value); err == nil {
 		s.selectStr = str
 	}
 }
 
-func (s search) limit(value interface{}) {
+func (s *search) limit(value interface{}) {
 	if str, err := getInterfaceAsString(value); err == nil {
 		s.limitStr = str
 	}
 }
 
-func (s search) offset(value interface{}) {
+func (s *search) offset(value interface{}) {
 	if str, err := getInterfaceAsString(value); err == nil {
 		s.offsetStr = str
 	}
 }
 
-func (s search) unscoped() {
+func (s *search) unscoped() {
 	s.unscope = true
 }
+
+func getInterfaceAsString(value interface{}) (str string, err error) {
+	switch value := value.(type) {
+	case string:
+		str = value
+	case int:
+		if value < 0 {
+			str = ""
+		} else {
+			str = strconv.Itoa(value)
+		}
+	default:
+		err = InvalidSql
+	}
+	return
+}
diff --git a/utils.go b/utils.go
index ea39a11a..d4897c13 100644
--- a/utils.go
+++ b/utils.go
@@ -3,8 +3,7 @@ package gorm
 import (
 	"bytes"
 	"database/sql"
-	"errors"
-	"fmt"
+
 	"reflect"
 	"strconv"
 	"strings"
@@ -50,22 +49,6 @@ func toSearchableMap(attrs ...interface{}) (result interface{}) {
 	return
 }
 
-func getInterfaceAsString(value interface{}) (str string, err error) {
-	switch value := value.(type) {
-	case string:
-		str = value
-	case int:
-		if value < 0 {
-			str = ""
-		} else {
-			str = strconv.Itoa(value)
-		}
-	default:
-		err = errors.New(fmt.Sprintf("Can't understand %v", value))
-	}
-	return
-}
-
 func setFieldValue(field reflect.Value, value interface{}) bool {
 	if field.IsValid() && field.CanAddr() {
 		switch field.Kind() {