Add Method NewRecord

README.md

@@ -137,6 +137,18 @@ user := User{Name: "jinzhu", Age: 18, Birthday: time.Now()}
 db.Save(&user)
 ```
 
+### NewRecord
+
+Returns true if object hasn’t been saved yet (`Id` is blank)
+
+```go
+user := User{Name: "jinzhu", Age: 18, Birthday: time.Now()}
+db.NewRecord(user) // => true
+
+db.Save(&user)
+db.NewRecord(user) // => false
+```
+
 ### Create With SubStruct
 
 Refer [Query With Related](#query-with-related) for how to find associations

gorm_test.go

@@ -161,11 +161,20 @@ func TestFirstAndLast(t *testing.T) {
 func TestCreateAndUpdate(t *testing.T) {
 	name, name2, new_name := "update", "update2", "new_update"
 	user := User{Name: name, Age: 1, PasswordHash: []byte{'f', 'a', 'k', '4'}}
+
+	if !db.NewRecord(user) {
+		t.Error("User should be new record")
+	}
+
 	db.Save(&user)
 	if user.Id == 0 {
 		t.Errorf("Should have ID after create")
 	}
 
+	if db.NewRecord(user) {
+		t.Error("User should not new record after save")
+	}
+
 	var u User
 	db.First(&u, user.Id)
 	if !reflect.DeepEqual(u.PasswordHash, []byte{'f', 'a', 'k', '4'}) {

main.go

@@ -238,6 +238,10 @@ func (s *DB) Rollback() *DB {
 	return s
 }
 
+func (s *DB) NewRecord(value interface{}) bool {
+	return s.clone().do(value).model.primaryKeyZero()
+}
+
 // Migrations
 func (s *DB) CreateTable(value interface{}) *DB {
 	return s.clone().do(value).createTable().db