relValue = joinSchema.ReflectValueOf(db.Statement.Context, currentReflectValue)
				if relValue.Kind() == reflect.Ptr {
					fullRelsName := utils.JoinNestedRelationNames(fullRels)
					// same nested structure
					if _, ok := joinedNestedSchemaMap[fullRelsName]; !ok {
						if value := reflect.ValueOf(values[idx]).Elem(); value.Kind() == reflect.Ptr && value.IsNil() {
							isNilPtrValue = true
							break

	if err != nil {
		t.Fatalf("failed to parse schema")
	}

	relSchema := user.Relationships.Relations["Creators"].FieldSchema
	if user != relSchema {
		t.Fatalf("schema should be same, expects %p but got %p", user, relSchema)
	}
}

type CreatedByModel struct {
	CreatedByID uint
	CreatedBy   *CreatedUser
}

type CreatedUser struct {
	gorm.Model
	CreatedByModel
}

		tx.Statement.AddClause(clause.Where{Exprs: conds})
	}
	return
}

// Not add NOT conditions
//
// Not works similarly to where, and has the same syntax.
//
//	// Find the first user with name not equal to jinzhu
//	db.Not("name = ?", "jinzhu").First(&user)
func (db *DB) Not(query interface{}, args ...interface{}) (tx *DB) {
	tx = db.getInstance()

}

// AddColumn create `name` column for value
func (m Migrator) AddColumn(value interface{}, name string) error {
	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
		// avoid using the same name field
		if stmt.Schema == nil {
			return errors.New("failed to get schema")
		}
		f := stmt.Schema.LookUpField(name)
		if f == nil {
			return fmt.Errorf("failed to look up field with name: %s", name)
		}

	AssertEqual(t, nil, err)
}

func TestMigrateWithDefaultValue(t *testing.T) {
	if DB.Dialector.Name() == "sqlserver" {
		// sqlserver driver treats NULL and 'NULL' the same
		t.Skip("skip sqlserver")
	}

	type NullModel struct {
		ID      uint
		Content string `gorm:"default:null"`
	}

	type NullStringModel struct {
		ID      uint

	Set                    func(context.Context, reflect.Value, interface{}) error
	Serializer             SerializerInterface
	NewValuePool           FieldNewValuePool

	// In some db (e.g. MySQL), Unique and UniqueIndex are indistinguishable.
	// When a column has a (not Mul) UniqueIndex, Migrator always reports its gorm.ColumnType is Unique.
	// It causes field unnecessarily migration.

		}

		if primaryKeyField == nil {
			schema.err = fmt.Errorf("invalid polymorphic type %v for %v on field %s, missing primaryKey field",
				relation.FieldSchema, schema, field.Name)
			return
		}

		// use same data type for foreign keys
		if copyableDataType(primaryKeyField.DataType) {
			relation.Polymorphic.PolymorphicID.DataType = primaryKeyField.DataType
		}