Fix error when handle relations

do.go

@@ -131,6 +131,7 @@ func (s *Do) saveBeforeAssociations() {
 func (s *Do) saveAfterAssociations() {
 	for _, field := range s.model.afterAssociations() {
 		reflect_value := reflect.ValueOf(field.Value)
+
 		switch reflect.TypeOf(field.Value).Kind() {
 		case reflect.Slice:
 			for i := 0; i < reflect_value.Len(); i++ {
@@ -143,7 +144,19 @@ func (s *Do) saveAfterAssociations() {
 			}
 		default:
 			do := &Do{chain: s.chain, db: s.db, driver: s.driver}
+			if reflect_value.CanAddr() {
+				s.model.setValueByColumn(field.foreignKey, s.model.primaryKeyValue(), field.Value)
 				do.setModel(field.Value).save()
+			} else {
+				dest_value := reflect.New(reflect.TypeOf(field.Value)).Elem()
+				m := &Model{data: field.Value, driver: s.driver}
+				for _, f := range m.columnsHasValue("update") {
+					dest_value.FieldByName(f.Name).Set(reflect.ValueOf(f.Value))
+				}
+
+				setFieldValue(dest_value.FieldByName(field.foreignKey), s.model.primaryKeyValue())
+				do.setModel(dest_value.Interface()).save()
+			}
 		}
 	}
 }
@@ -311,12 +324,8 @@ func (s *Do) getForeignKey(from *Model, to *Model, foreign_key string) (err erro
 		} else {
 			foreign_value = value
 		}
-	} else if has_column, is_slice, value := to.ColumnAndValue(foreign_key); has_column {
-		if is_slice {
+	} else if has_column, _, _ := to.ColumnAndValue(foreign_key); has_column {
 		foreign_value = from.primaryKeyValue()
-		} else {
-			foreign_value = value
-		}
 	} else {
 		err = errors.New("Can't find valid foreign Key")
 	}

gorm_test.go

@@ -25,11 +25,18 @@ type User struct {
 	BillingAddressId  int64     // Embedded struct's foreign key
 	ShippingAddress   Address   // Embedded struct
 	ShippingAddressId int64     // Embedded struct's foreign key
+	CreditCard        CreditCard
+}
+
+type CreditCard struct {
+	Id     int64
+	Number string
+	UserId int64
 }
 
 type Email struct {
 	Id         int64
-	UserId     int64 // Foreign key for above embedded structs
+	UserId     int64
 	Email      string
 	Subscribed bool
 }
@@ -87,6 +94,7 @@ func init() {
 	db.Exec("drop table products;")
 	db.Exec("drop table emails;")
 	db.Exec("drop table addresses")
+	db.Exec("drop table credit_cards")
 
 	err = db.CreateTable(&User{}).Error
 	if err != nil {
@@ -108,6 +116,11 @@ func init() {
 		panic(fmt.Sprintf("No error should happen when create table, but got %+v", err))
 	}
 
+	err = db.CreateTable(CreditCard{}).Error
+	if err != nil {
+		panic(fmt.Sprintf("No error should happen when create table, but got %+v", err))
+	}
+
 	var shortForm = "2006-01-02 15:04:05"
 	t1, _ = time.Parse(shortForm, "2000-10-27 12:02:40")
 	t2, _ = time.Parse(shortForm, "2002-01-01 00:00:00")
@@ -1134,6 +1147,7 @@ func TestRelated(t *testing.T) {
 		BillingAddress:  Address{Address1: "Billing Address - Address 1"},
 		ShippingAddress: Address{Address1: "Shipping Address - Address 1"},
 		Email:           []Email{{Email: "jinzhu@example.com"}, {Email: "jinzhu-2@example@example.com"}},
+		CreditCard:      CreditCard{Number: "1234567890"},
 	}
 
 	db.Save(&user)
@@ -1155,4 +1169,12 @@ func TestRelated(t *testing.T) {
 	if user2.Id != user.Id || user2.Name != user.Name {
 		t.Errorf("Should get user from email correctly")
 	}
+
+	var credit_card CreditCard
+	var user3 User
+	db.First(&credit_card, "number = ?", "1234567890")
+	db.Model(&credit_card).Related(&user3)
+	if user3.Id != user.Id || user3.Name != user.Name {
+		t.Errorf("Should get user from credit card correctly")
+	}
 }

model.go

@@ -120,6 +120,10 @@ func (m *Model) fields(operation string) (fields []Field) {
 						value.Set(reflect.ValueOf(time.Now()))
 					}
 				case "update":
+					if field.AutoCreateTime && time_value.IsZero() {
+						value.Set(reflect.ValueOf(time.Now()))
+					}
+
 					if field.AutoUpdateTime {
 						value.Set(reflect.ValueOf(time.Now()))
 					}
@@ -153,6 +157,10 @@ func (m *Model) fields(operation string) (fields []Field) {
 							field.foreignKey = p.Name + "Id"
 							field.beforeAssociation = true
 						} else {
+							foreign_key := typ.Name() + "Id"
+							if reflect.New(field_value.Type()).Elem().FieldByName(foreign_key).IsValid() {
+								field.foreignKey = foreign_key
+							}
 							field.afterAssociation = true
 						}
 					}