Florian,
Do you mean WITH HOLD cursors (+ FOR UPDATE) can also be used to do
DELETE/UPDATE WHERE CURRENT OF (i.e. outside transactions) ?
From my experience this is an Informix-only feature, but if PostgreSQL
supports that it would help a lot to migrate existing applications.
I understand it's
Just found this in the doc:
WITH HOLD may not be specified when the query includes FOR UPDATE or FOR SHARE
Here is what the Informix doc says about WITH HOLD + FOR UPDATE:
It is possible to declare an update cursor with the WITH HOLD keywords,
but the only reason to do so is to break a long
Sebastien FLAESCH wrote:
Forget this one, just missing the WITH HOLD option... Must teach myself a bit
more before sending further mails. Seb
AFAIK you cannot use WITH HOLD together with updateable cursors.
I might be wrong, though...
regards, Florian Pflug
---(end of
Sebastien FLAESCH wrote:
Just looked at the new features of 8.3 and realized that positioned
updates/deletes is now possible with this new release...
We would use that if we could define the cursor name with a libpq function.
I don't understand. When you open a cursor with DECLARE CURSOR,
Thanks Heikki for this quick answer.
Actually we do the following lipq calls:
- PQPrepare(... SELECT ... FROM ... FOR UPDATE ... )
- PQexecPrepared(...)
- PQntuples(...) / PQgetvalue(...)
i.e. we don't use the DECLARE CURSOR instruction, we just prepare/execute
the plain SELECT statement (with
Tom Lane wrote:
Sebastien FLAESCH [EMAIL PROTECTED] writes:
Does a simple PQPrepare() with a SELECT statement not create a cursor on
the server side?
No. A prepared statement is just a query plan, not a query-in-progress.
Yes of course, I meant PQprepare() + PQexecPrepared() ...
The
Forget this one, just missing the WITH HOLD option...
Must teach myself a bit more before sending further mails.
Seb
Sebastien FLAESCH wrote:
Ok...
Tested with 8.2.3:
Actually you can't DECLARE a cursor outside a transaction:
test1= declare c1 cursor for select * from dbit2;
ERROR: DECLARE
Ok...
Tested with 8.2.3:
Actually you can't DECLARE a cursor outside a transaction:
test1= declare c1 cursor for select * from dbit2;
ERROR: DECLARE CURSOR may only be used in transaction blocks
That's the main reason why we don't use DECLARE CURSOR...
I understand we could use DECLARE
Sebastien FLAESCH [EMAIL PROTECTED] writes:
Does a simple PQPrepare() with a SELECT statement not create a cursor on
the server side?
No. A prepared statement is just a query plan, not a query-in-progress.
The Bind/Execute messages sent by PQexecPrepared create something akin
to a cursor, but
