Gorm db.CommonDB() no longer works in gorm v2.

db.CommonDB() no longer works in gorm v2.

if tx, ok := DB.CommonDB().(*sql.Tx) ; ok { ... }

can't work.

Any alternative way to get the underlying sql.Tx instance?

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Comment From: li-jin-gou

@liush5 hello, you can look this doc https://gorm.io/zh_CN/docs/generic_interface.html

Comment From: liush5-zz

@liush5 hello, you can look this doc https://gorm.io/zh_CN/docs/generic_interface.html

@li-jin-gou thanks,but i still have question

for example：

type Payment struct {
    UserId int64
    Amount int64
}

func SendPayment(gdb *gorm.DB, user_id, amount int64) error {
    tx := gdb.Begin()
    defer tx.Rollback()

    // question: gorm.Db how to get sql.Tx ?
    b, err := GetBalance(??, user_id)
    if err != nil {
        return err
    }
    if b < amount {
        return errors.New("insufficient funds")
    }

    p := Payment{user_id, amount}
    gdb.Save(p)

    return gdb.Commit().Error
}

func GetBalance(tx *sql.Tx, userId int64) int64 {
    return 20
}

question: gorm.DB how to get sql.Tx Instance ？

Comment From: li-jin-gou

@liush5 hello, you can look this doc https://gorm.io/zh_CN/docs/generic_interface.html

@li-jin-gou thanks,but i still have question

for example：

```go type Payment struct { UserId int64 Amount int64 }

func SendPayment(gdb *gorm.DB, user_id, amount int64) error { tx := gdb.Begin() defer tx.Rollback()

// question: gorm.Db how to get sql.Tx ? b, err := GetBalance(??, user_id) if err != nil { return err } if b < amount { return errors.New("insufficient funds") }

p := Payment{user_id, amount} gdb.Save(p)

return gdb.Commit().Error }

func GetBalance(tx *sql.Tx, userId int64) int64 { return 20 } ```

question: gorm.DB how to get sql.Tx Instance ？

    txDB := DB.Begin()

    tx,ok := txDB.Statement.ConnPool.(*sql.Tx)

    if !ok{
        // deal type assert error 
    }