* Transactions, Nested Transactions, Save Point, RollbackTo to Saved Point
* Context, Prepared Statement Mode, DryRun Mode
* Batch Insert, FindInBatches, Find To Map
* SQL Builder, Upsert, Locking, Optimizer/Index/Comment Hints, NamedArg, Search/Update/Create with SQL Expr
* Composite Primary Key
* Auto Migrations
* Logger
* Extendable, flexible plugin API: Database Resolver (Multiple Databases, Read/Write Splitting) / Prometheus…

	err := DB.Model(&User{}).Where("name like ?", "pluck_with_select%").Select("age + 1 as user_age").Pluck("user_age", &userAges).Error
	if err != nil {
		t.Fatalf("got error when pluck user_age: %v", err)
	}

	sort.Ints(userAges)

	AssertEqual(t, userAges, []int{26, 27})
}

func TestSelectWithVariables(t *testing.T) {
	DB.Save(&User{Name: "select_with_variables"})

// advanced techniques like specifying lock strength and optimizer hints. See the
// [docs] for more depth.
//
//	// add a simple limit clause
//	db.Clauses(clause.Limit{Limit: 1}).Find(&User{})
//	// tell the optimizer to use the `idx_user_name` index
//	db.Clauses(hints.UseIndex("idx_user_name")).Find(&User{})
//	// specify the lock strength to UPDATE

	tracer := Tracer{
		Logger: DB.Config.Logger,
		Test: func(ctx context.Context, begin time.Time, fc func() (sql string, rowsAffected int64), err error) {
			sql, _ := fc()
			if strings.HasPrefix(sql, "ALTER TABLE \"migrate_ints\" ALTER COLUMN \"int8\" TYPE smallint") {
				t.Fatalf("shouldn't execute ALTER COLUMN TYPE if such type is already existed in DB schema: sql: %s",
					sql)
			}
		},
	}

	DB.Migrator().DropTable(&MigrateInt{})