diff --git a/sql.go b/interface.go
similarity index 100%
rename from sql.go
rename to interface.go
diff --git a/private.go b/main_private.go
similarity index 94%
rename from private.go
rename to main_private.go
index 2b6bceb0..fe198c1d 100644
--- a/private.go
+++ b/main_private.go
@@ -40,10 +40,6 @@ func (s *DB) err(err error) error {
 	return err
 }
 
-func (s *DB) hasError() bool {
-	return s.Error != nil
-}
-
 func (s *DB) print(v ...interface{}) {
 	s.parent.logger.(logger).Print(v...)
 }
diff --git a/scope.go b/scope.go
index d73ddb10..5ea82983 100644
--- a/scope.go
+++ b/scope.go
@@ -24,6 +24,10 @@ type Scope struct {
 	skipLeft bool
 }
 
+func (scope *Scope) Quote(str string) string {
+	return scope.Dialect().Quote(str)
+}
+
 func (db *DB) NewScope(value interface{}) *Scope {
 	db.Value = value
 	return &Scope{db: db, Search: db.search, Value: value, _values: map[string]interface{}{}}
@@ -71,7 +75,7 @@ func (scope *Scope) Log(v ...interface{}) {
 }
 
 func (scope *Scope) HasError() bool {
-	return scope.db.hasError()
+	return scope.db.Error != nil
 }
 
 func (scope *Scope) PrimaryKey() string {
diff --git a/scope_condition.go b/scope_condition.go
index fd820c8f..21f6d5a8 100644
--- a/scope_condition.go
+++ b/scope_condition.go
@@ -10,10 +10,6 @@ import (
 	"strings"
 )
 
-func (scope *Scope) Quote(str string) string {
-	return scope.Dialect().Quote(str)
-}
-
 func (scope *Scope) primaryCondiation(value interface{}) string {
 	return fmt.Sprintf("(%v = %v)", scope.Quote(scope.PrimaryKey()), value)
 }