Confusion about transaction code:

My transaction code:

try {
    const cn = await pool.getConnection()
    await cn.beginTransaction()

    await cn.execute(' ...
    await cn.execute(' ...

    await cn.commit()
}
catch {
    await cn.rollback()
}

But am I wrong? Should it be:

const cn = await pool.getConnection()
try {
    await cn.beginTransaction()

    await cn.execute(' ...
    await cn.execute(' ...

    await cn.commit()
}
catch {
    await cn.rollback()
}

But wait! Should it be?

const cn = await pool.getConnection()
await cn.beginTransaction()
try {
    await cn.execute(' ...
    await cn.execute(' ...

    await cn.commit()
}
catch {
    await cn.rollback()
}

I’m afraid I don’t know the answer. Thanks in advance anyone who can advise. (It may help others also?)

[sidorares]

there was a discussion somewhere here about possible better helper api that would handle this pattern, for example something similar to https://github.com/porsager/postgres#transactions ( I’ve started some initial work here )

[sidorares]

beginTransaction / commit / rollback are just simple helpers to perform START TRANSACTION / COMMIT / ROLLBACK queries

To me 3rd example is the most correct but I’m not an SQL / mysql expert

Possible reasons why pool.getConnection() can fail: network error in the process of getting a new connection, too many connections limit reached (server side), client side limit on number of open connections

Not sure when START TRANSACTION can fail ( reasons other than connection is killed because of network error or other client KILL thread_id ) but I guess rollback only makes sense after successful START TRANSACTION