// Replace
	toy2 := Toy{Name: "toy-has-many-replace"}

	if err := DB.Model(&user2).Association("Toys").Replace(&toy2); err != nil {
		t.Fatalf("Error happened when append toy, got %v", err)
	}

	if toy2.ID == 0 {
		t.Fatalf("toy2's ID should be created")
	}

	user.Toys = []Toy{toy2}
	CheckUser(t, user2, user)

	AssertAssociationCount(t, user2, "Toys", 1, "AfterReplace")

	// Delete

			}
		}
	})

	t.Run("Toys", func(t *testing.T) {
		if len(user.Toys) != len(expect.Toys) {
			t.Fatalf("toys should equal, expect: %v, got %v", len(expect.Toys), len(user.Toys))
		}

		sort.Slice(user.Toys, func(i, j int) bool {
			return user.Toys[i].ID > user.Toys[j].ID
		})

		sort.Slice(expect.Toys, func(i, j int) bool {
			return expect.Toys[i].ID > expect.Toys[j].ID
		})

			UserID int
			Toy    Toy   `gorm:"polymorphic:Owner;"`
			Toys   []Toy `gorm:"polymorphic:Owner;"`
		}
		Toys []Toy `gorm:"polymorphic:Owner;"`
	}

	s, err := schema.Parse(&User{}, &sync.Map{}, schema.NamingStrategy{})
	if err != nil {
		t.Fatalf("Failed to parse schema, got error %v", err)
	}

	checkEmbeddedRelations(t, s.Relationships.EmbeddedRelations, map[string]EmbeddedRelations{
		"Cat": {

		*GetUser("delete_slice_with_associations1", Config{Account: true, Pets: 4, Toys: 1, Company: true, Manager: true, Team: 1, Languages: 1, Friends: 4}),
		*GetUser("delete_slice_with_associations2", Config{Account: true, Pets: 3, Toys: 2, Company: true, Manager: true, Team: 2, Languages: 2, Friends: 3}),
		*GetUser("delete_slice_with_associations3", Config{Account: true, Pets: 2, Toys: 3, Company: true, Manager: true, Team: 3, Languages: 3, Friends: 2}),

	var updatedUser User
	if err := DB.Preload("Pets").Preload("Toys").Where("id = ?", user.ID).First(&updatedUser).Error; err != nil {
		t.Fatalf("failed to find updated user: %v", err)
	}

	if len(updatedUser.Pets) != 2 {
		t.Fatalf("expected 2 pets, got %d", len(updatedUser.Pets))
	}

	if len(updatedUser.Toys) != 2 {
		t.Fatalf("expected 2 toys, got %d", len(updatedUser.Toys))
	}
}

			relationships.Relations[relation.Name] = relation
		}
	}
}

// User has many Toys, its `Polymorphic` is `Owner`, Pet has one Toy, its `Polymorphic` is `Owner`
//
//	type User struct {
//	  Toys []Toy `gorm:"polymorphic:Owner;"`
//	}
//	type Pet struct {
//	  Toy Toy `gorm:"polymorphic:Owner;"`
//	}
//	type Toy struct {
//	  OwnerID   int
//	  OwnerType string
//	}

	result.Languages = append(user.Languages, result.Languages...)
	result.Toys = append(user.Toys, result.Toys...)

	sort.Slice(result.Languages, func(i, j int) bool {
		return strings.Compare(result.Languages[i].Code, result.Languages[j].Code) > 0
	})

	sort.Slice(result.Toys, func(i, j int) bool {
		return result.Toys[i].ID < result.Toys[j].ID
	})

	sort.Slice(result2.Languages, func(i, j int) bool {

		Preload("Toys", func(db *gorm.DB) *gorm.DB {
			return db.Table("toys").Select("name")
		}).Count(&count12).Error; err == nil {
		t.Errorf("error should raise when using preload without schema")
	}

	var count13 int64
	if err := DB.Model(User{}).
		Where("name in ?", []string{user1.Name, user2.Name, user3.Name}).
		Preload("Toys", func(db *gorm.DB) *gorm.DB {

And an `APIRoute` subclass to use that custom request class.

### Create a custom `GzipRequest` class { #create-a-custom-gziprequest-class }

/// tip

This is a toy example to demonstrate how it works, if you need Gzip support, you can use the provided [`GzipMiddleware`](../advanced/middleware.md#gzipmiddleware).

///

	}

	if tables, err := DB.Migrator().GetTables(); err != nil {
		t.Fatalf("Failed to get database all tables, but got error %v", err)
	} else {
		for _, t1 := range []string{"users", "accounts", "pets", "companies", "toys", "languages", "tools"} {
			hasTable := false
			for _, t2 := range tables {
				if t2 == t1 {
					hasTable = true
					break
				}
			}
			if !hasTable {