Document how RunInTransaction works

[viblo]

We have a small go coding test for potential new employees at my company. From what I can tell a lot of our candidates dont understand how RunInTransaction works. The "tricky" part is that you have to actually use the inner pg.Tx to make use of the transaction which many of them doesnt seem to get. Now since this is a coding test it doesnt have any critical effect except it makes it easy for us to filter them out, but I suspect that a lot of normal users of go-pg will make the same mistake.

What Ive seen people do is this:

db.RunInTransaction(func(tx *pg.Tx) error {
    db.Exec("insert into users (a) values(1)")
    tx.Rollback()
    return nil
})

Instead you should of course do it this way if you want the insert to be rollbacked:

db.RunInTransaction(func(tx *pg.Tx) error {
    tx.Exec("insert into users (a) values(1)")
    tx.Rollback()
    return nil
})

Maybe you can add an example / clarify the documentation of this function? I think that can save a lot of tricky debugging for unexperienced users of this library.

[vmihailenco]

Thanks for feedback, added https://godoc.org/gopkg.in/pg.v4#example-DB-RunInTransaction