func (m *Man) BeforeUpdate(tx *gorm.DB) (err error) {
	if !tx.Statement.Changed("age") {
		return nil
	}
	return nil
}

func TestSubModel(t *testing.T) {
	man := Man{Age: 18, Name: "random-name"}
	if err := DB.Create(&man).Error; err != nil {
		t.Fatalf("unexpected error: %v", err)
	}

	if err := DB.Model(&man).Where("id = ?", man.ID).Updates(struct {
		Age int

			t.Errorf("expect %#v but got %#v", conn.expect, conn.got)
		}
	}()

	db, err := gorm.Open(mysql.New(mysql.Config{Conn: conn, DisableWithReturning: true}))
	db.Logger = DB.Logger
	if err != nil {
		t.Fatalf("Should open db success, but got %v", err)
	}

	tx := db.Begin()
	user := *GetUser("transaction", Config{})

	if err = tx.Save(&user).Error; err != nil {

	return namer.TableName("user")
}

func TestTableWithNamer(t *testing.T) {
	db, _ := gorm.Open(tests.DummyDialector{}, &gorm.Config{
		NamingStrategy: schema.NamingStrategy{
			TablePrefix: "t_",
		},
	})

	sql := db.ToSQL(func(tx *gorm.DB) *gorm.DB {
		return tx.Model(&UserWithTableNamer{}).Find(&UserWithTableNamer{})
	})

			queryFn: func(tx *gorm.DB) *gorm.DB {
				return tx.Scopes(
					func(d *gorm.DB) *gorm.DB { return d.Model(&Language{}) },
					func(d *gorm.DB) *gorm.DB {
						return d.
							Or(DB.Scopes(
								func(d *gorm.DB) *gorm.DB { return d.Where("a = 1") },
								func(d *gorm.DB) *gorm.DB { return d.Where("b = 2") },
							)).
							Or("c = 3")
					},
					func(d *gorm.DB) *gorm.DB { return d.Where("d = 4") },

			db.Mux.RUnlock()
			return stmt, stmt.Error()
		}
	}
	db.Mux.RUnlock()

	// retry
	db.Mux.Lock()
	if db.Stmts != nil {
		if stmt, ok := db.Stmts.Get(query); ok && (!stmt.Transaction || isTransaction) {
			db.Mux.Unlock()
			return stmt, stmt.Error()
		}
	}

	return db.Stmts.New(ctx, query, isTransaction, conn, db.Mux)
}

import (
	"gorm.io/gorm"
)

func RowQuery(db *gorm.DB) {
	if db.Error == nil {
		BuildQuerySQL(db)
		if db.DryRun || db.Error != nil {
			return
		}

		if isRows, ok := db.Get("rows"); ok && isRows.(bool) {
			db.Statement.Settings.Delete("rows")
			db.Statement.Dest, db.Error = db.Statement.ConnPool.QueryContext(db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...)
		} else {

				t.Fatalf("Failed to get table %v when GetTables", t1)
			}
		}
	}

	for _, m := range allModels {
		if !DB.Migrator().HasTable(m) {
			t.Fatalf("Failed to create table for %#v", m)
		}
	}

	DB.Scopes(func(db *gorm.DB) *gorm.DB {
		return db.Table("ccc")
	}).Migrator().CreateTable(&Company{})

	if !DB.Migrator().HasTable("ccc") {
		t.Errorf("failed to create table ccc")
	}

	for _, indexes := range [][2]string{

	DB.Create(&user)

	// Update a single field of the user and verify that the changed address is not stored.
	newAge := uint(100)
	user.Account.Number = "new_account_number"
	db := DB.Model(&user).UpdateColumns(User{Age: newAge})

	if db.RowsAffected != 1 {
		t.Errorf("Expected RowsAffected=1 but instead RowsAffected=%v", db.RowsAffected)
	}

	// Verify that Age now=`newAge`.

	}
}

func TestDeeplyNestedTransactionWithBlockAndWrappedCallback(t *testing.T) {
	transaction := func(ctx context.Context, db *gorm.DB, callback func(ctx context.Context, db *gorm.DB) error) error {
		return db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
			return callback(ctx, tx)
		})
	}
	var (
		user  = *GetUser("transaction-nested", Config{})
		user1 = *GetUser("transaction-nested-1", Config{})

package callbacks

import (
	"gorm.io/gorm"
)

func BeginTransaction(db *gorm.DB) {
	if !db.Config.SkipDefaultTransaction && db.Error == nil {
		if tx := db.Begin(); tx.Error == nil {
			db.Statement.ConnPool = tx.Statement.ConnPool
			db.InstanceSet("gorm:started_transaction", true)
		} else if tx.Error == gorm.ErrInvalidTransaction {
			tx.Error = nil
		} else {
			db.Error = tx.Error
		}
	}
}