From 186e8a9e14578c63715444d217294065be072805 Mon Sep 17 00:00:00 2001
From: Cr <631807682@qq.com>
Date: Tue, 18 Oct 2022 11:58:42 +0800
Subject: [PATCH] fix: association without pks (#5779)

---
 callbacks/associations.go  | 10 +++++++--
 tests/associations_test.go | 42 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/callbacks/associations.go b/callbacks/associations.go
index 00e00fcc3..9d7c1412e 100644
--- a/callbacks/associations.go
+++ b/callbacks/associations.go
@@ -208,7 +208,10 @@ func SaveAfterAssociations(create bool) func(db *gorm.DB) {
 
 							cacheKey := utils.ToStringKey(relPrimaryValues...)
 							if len(relPrimaryValues) != len(rel.FieldSchema.PrimaryFields) || !identityMap[cacheKey] {
-								identityMap[cacheKey] = true
+								if cacheKey != "" { // has primary fields
+									identityMap[cacheKey] = true
+								}
+
 								if isPtr {
 									elems = reflect.Append(elems, elem)
 								} else {
@@ -294,7 +297,10 @@ func SaveAfterAssociations(create bool) func(db *gorm.DB) {
 
 							cacheKey := utils.ToStringKey(relPrimaryValues...)
 							if len(relPrimaryValues) != len(rel.FieldSchema.PrimaryFields) || !identityMap[cacheKey] {
-								identityMap[cacheKey] = true
+								if cacheKey != "" { // has primary fields
+									identityMap[cacheKey] = true
+								}
+
 								distinctElems = reflect.Append(distinctElems, elem)
 							}
 
diff --git a/tests/associations_test.go b/tests/associations_test.go
index 42b32afc0..4c9076dab 100644
--- a/tests/associations_test.go
+++ b/tests/associations_test.go
@@ -348,3 +348,45 @@ func TestAssociationEmptyQueryClause(t *testing.T) {
 		AssertEqual(t, len(orgs), 0)
 	}
 }
+
+type AssociationEmptyUser struct {
+	ID   uint
+	Name string
+	Pets []AssociationEmptyPet
+}
+
+type AssociationEmptyPet struct {
+	AssociationEmptyUserID *uint  `gorm:"uniqueIndex:uniq_user_id_name"`
+	Name                   string `gorm:"uniqueIndex:uniq_user_id_name;size:256"`
+}
+
+func TestAssociationEmptyPrimaryKey(t *testing.T) {
+	if DB.Dialector.Name() != "mysql" {
+		t.Skip()
+	}
+	DB.Migrator().DropTable(&AssociationEmptyUser{}, &AssociationEmptyPet{})
+	DB.AutoMigrate(&AssociationEmptyUser{}, &AssociationEmptyPet{})
+
+	id := uint(100)
+	user := AssociationEmptyUser{
+		ID:   id,
+		Name: "jinzhu",
+		Pets: []AssociationEmptyPet{
+			{AssociationEmptyUserID: &id, Name: "bar"},
+			{AssociationEmptyUserID: &id, Name: "foo"},
+		},
+	}
+
+	err := DB.Session(&gorm.Session{FullSaveAssociations: true}).Create(&user).Error
+	if err != nil {
+		t.Fatalf("Failed to create, got error: %v", err)
+	}
+
+	var result AssociationEmptyUser
+	err = DB.Preload("Pets").First(&result, &id).Error
+	if err != nil {
+		t.Fatalf("Failed to find, got error: %v", err)
+	}
+
+	AssertEqual(t, result, user)
+}