Make Replace support other associations

association.go

@@ -124,7 +124,6 @@ func (association *Association) Delete(values ...interface{}) *Association {
 func (association *Association) Replace(values ...interface{}) *Association {
 	relationship := association.Field.Relationship
 	scope := association.Scope
-	if relationship.Kind == "many_to_many" {
 	field := association.Field.Field
 
 	oldPrimaryKeys := association.getPrimaryKeys(relationship.AssociationForeignFieldNames, field.Interface())
@@ -151,7 +150,9 @@ func (association *Association) Replace(values ...interface{}) *Association {
 	}
 
 	query := scope.NewDB()
+	var foreignKeyMap = map[string]string{}
 	for idx, foreignKey := range relationship.ForeignDBNames {
+		foreignKeyMap[foreignKey] = ""
 		if field, ok := scope.FieldByName(relationship.ForeignFieldNames[idx]); ok {
 			query = query.Where(fmt.Sprintf("%v = ?", scope.Quote(foreignKey)), field.Field.Interface())
 		}
@@ -161,9 +162,11 @@ func (association *Association) Replace(values ...interface{}) *Association {
 		sql := fmt.Sprintf("%v NOT IN (%v)", toQueryCondition(scope, relationship.AssociationForeignDBNames), toQueryMarks(addedPrimaryKeys))
 		query = query.Where(sql, toQueryValues(addedPrimaryKeys)...)
 	}
+
+	if relationship.Kind == "many_to_many" {
 		association.setErr(relationship.JoinTableHandler.Delete(relationship.JoinTableHandler, query, relationship))
-	} else {
-		association.setErr(errors.New("replace only support many to many"))
+	} else if relationship.Kind == "has_one" || relationship.Kind == "has_many" {
+		query.Update(foreignKeyMap)
 	}
 	return association
 }

association_test.go

@@ -51,15 +51,20 @@ func TestHasOne(t *testing.T) {
 	}
 
 	// Replace
-	// DB.Model(&post).Association("Category").Replace(&Category{
-	// 	Name: "Category 3",
-	// })
+	var category3 = Category{
+		Name: "Category 3",
+	}
+	DB.Model(&post).Association("Category").Replace(&category3)
 
-	// var category3 Category
-	// DB.Model(&post).Related(&category3)
-	// if category3.Name != "Category 3" {
-	// 	t.Errorf("Category should be updated with Replace")
-	// }
+	if category3.Id == 0 {
+		t.Errorf("Category should has ID when created with Replace")
+	}
+
+	var category31 Category
+	DB.Model(&post).Related(&category31)
+	if category31.Name != "Category 3" {
+		t.Errorf("Category should be updated with Replace")
+	}
 
 	// Delete
 	// Clear