for i := 0; i < 100; i++ {
		wg.Add(1)
		go func() {
			user := User{Name: "jinzhu"}
			tx.Create(&user)

			var result User
			tx.First(&result)
			wg.Done()
		}()
	}
	wg.Wait()

	conn, ok := tx.ConnPool.(*gorm.PreparedStmtDB)
	AssertEqual(t, ok, true)
	AssertEqual(t, len(conn.Stmts), 2)
	for _, stmt := range conn.Stmts {
		if stmt == nil {
			t.Fatalf("stmt cannot bee nil")
		}

		db.Mux.RUnlock()
		// wait for other goroutines prepared
		<-stmt.prepared
		if stmt.prepareErr != nil {
			return Stmt{}, stmt.prepareErr
		}

		return *stmt, nil
	}
	db.Mux.RUnlock()

	db.Mux.Lock()
	// double check
	if stmt, ok := db.Stmts[query]; ok && (!stmt.Transaction || isTransaction) {
		db.Mux.Unlock()
		// wait for other goroutines prepared
		<-stmt.prepared

package clause

const (
	LockingStrengthUpdate    = "UPDATE"
	LockingStrengthShare     = "SHARE"
	LockingOptionsSkipLocked = "SKIP LOCKED"
	LockingOptionsNoWait     = "NOWAIT"
)

type Locking struct {
	Strength string
	Table    Table
	Options  string
}

// Name where clause name
func (locking Locking) Name() string {
	return "FOR"
}

// Build build where clause
func (locking Locking) Build(builder Builder) {

        env:
          POSTGRES_PASSWORD: gorm
          POSTGRES_USER: gorm
          POSTGRES_DB: gorm
          TZ: Asia/Shanghai
        ports:
          - 9920:5432
        # Set health checks to wait until postgres has started
        options: >-
          --health-cmd pg_isready
          --health-interval 10s
          --health-timeout 5s
          --health-retries 5

    steps:

			defer wg.Done()
			var user2 []User
			tx := DB.Where("id = ?", 1).Session(&gorm.Session{})

			if err := tx.Preload("Team").Find(&user2).Error; err != nil {
				t.Error(err)
			}
		}()
	}
	wg.Wait()
}

func TestPreloadWithDiffModel(t *testing.T) {
	user := *GetUser("preload_with_diff_model", Config{Account: true})

	if err := DB.Create(&user).Error; err != nil {

		},
		{
			[]clause.Interface{clause.Select{}, clause.From{}, clause.Locking{Strength: clause.LockingStrengthUpdate, Options: clause.LockingOptionsNoWait}},
			"SELECT * FROM `users` FOR UPDATE NOWAIT", nil,
		},
		{
			[]clause.Interface{clause.Select{}, clause.From{}, clause.Locking{Strength: clause.LockingStrengthUpdate, Options: clause.LockingOptionsSkipLocked}},
			"SELECT * FROM `users` FOR UPDATE SKIP LOCKED", nil,

	} else {
		schemaCacheKey = modelType
	}

	// Load exist schema cache, return if exists
	if v, ok := cacheStore.Load(schemaCacheKey); ok {
		s := v.(*Schema)
		// Wait for the initialization of other goroutines to complete
		<-s.initialized
		return s, s.err
	}

	modelValue := reflect.New(modelType)
	tableName := namer.TableName(modelType.Name())

		wg.Add(1)
		go func(user User, language Language) {
			err := db.Model(&user).Association("Languages").Append(&language)
			AssertEqual(t, err, nil)

			wg.Done()
		}(user, languages[i])
	}
	wg.Wait()

	var find User
	err = db.Preload(clause.Associations).Where("id = ?", user.ID).First(&find).Error
	AssertEqual(t, err, nil)
	AssertAssociationCount(t, find, "Languages", int64(count), "after concurrent append")
}