Re: handling transactions from C (libpq)
On Fri, Aug 09, 2002 at 05:35:00PM +0300, am@fx.ro wrote:
Please tell me, is there a way to abort only the last command of
a transaction? Or, is it possible to use "subtransactions"
inside a transaction?
No, at least not yet.
By the way, the version of Postgres you're using is well and truly
ancient, and should probably be upgraded. Given that you're using
Debian, just upgrading tot he latest -stable should do the trick for
you.
A
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Andrew Sullivan 87 Mowat Avenue
Liberty RMS Toronto, Ontario Canada
<andrew@libertyrms.info> M6K 3E3
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Reply to msg id not found: 20020809173500.A297@cotoReference msg id not found: 20020809173500.A297@coto
am@fx.ro a écrit:
...
I want the user to be able to choose between commiting and
rollbacking the changes he/she has made to the table.
Therefore:
1. when the user presses KEY_END, I execute: PQexec(conn,"commit")
2. when the user presses KEY_HOME, I execute: PQexec(conn,"rollback")Here comes the problem:
Imagine the user has inserted 5 new records. He enters the 6th record
but makes a mistake ( for example enters a bad date format ).
The program generates an INSERT command and executes it with PQexec.
An error is generated and the program prints it on the screen.Because of the error, the transaction is compromised and has to be
aborted, and the user has to enter the first 5 records... again...
Very annoying.
The program should report the error and let the user correct the
typing mistake, without affecting the other records (although
there is only one transaction).
But, I don't know how to achieve this.
your client should keep the records in a temporary area (table or local structure)
or "a pre-commit table",
and restore the records to the screen if an error occurs.
transaction is not an undo.
(I've noticed that even in psql if I enter an erroneous insert
command, the transaction is left in an unusual state , and queries
are no longer executed until "rollback" or "abort" is entered).
Please tell me, is there a way to abort only the last command of
a transaction? Or, is it possible to use "subtransactions"
inside a transaction?
As far as I know, subtransactions are not supported
Import Notes
Reference msg id not found: 20020809173500.A297@coto | Resolved by subject fallback