Обсуждение: pass open cursor via USING in execute staement
The following documentation comment has been logged on the website: Page: https://www.postgresql.org/docs/15/plpgsql-statements.html Description: Should be documented if this statement is allowed or not (if not, maybe set as desired feature :-) ) EXECUTE format('update %I set col1=$1, col2=now() WHERE current of $3', tabname) USING myVal, myOpenCursor;
On Wed, 2023-05-31 at 22:57 +0000, PG Doc comments form wrote: > Page: https://www.postgresql.org/docs/15/plpgsql-statements.html > > Should be documented if this statement is allowed or not (if not, maybe set > as desired feature :-) ) > > EXECUTE format('update %I set col1=$1, col2=now() WHERE current of $3', > tabname) > USING myVal, myOpenCursor; That is not supported. Parameters can only be used in a place where constants (SQL literals) might appear, not instead of identifiers (names of tables, columns etc.) I looked, and that is really not documented anywhere. One of PREPARE or the extended query protocol might be good places. Yours, Laurenz Albe
Yes, I agree, but also in cursor page.
Talking about cursor I can't find example that shows how pass a bounded cursor to a function or procedure (must be already open? must be declared in some specific way?)
Il giorno gio 1 giu 2023 alle ore 16:23 Laurenz Albe <laurenz.albe@cybertec.at> ha scritto:
On Wed, 2023-05-31 at 22:57 +0000, PG Doc comments form wrote:
> Page: https://www.postgresql.org/docs/15/plpgsql-statements.html
>
> Should be documented if this statement is allowed or not (if not, maybe set
> as desired feature :-) )
>
> EXECUTE format('update %I set col1=$1, col2=now() WHERE current of $3',
> tabname)
> USING myVal, myOpenCursor;
That is not supported. Parameters can only be used in a place where constants
(SQL literals) might appear, not instead of identifiers (names of tables, columns etc.)
I looked, and that is really not documented anywhere.
One of PREPARE or the extended query protocol might be good places.
Yours,
Laurenz Albe
Domenico L.
per stupire mezz'ora basta un libro di storia,
io cercai di imparare la Treccani a memoria... [F.d.A.]
per stupire mezz'ora basta un libro di storia,
io cercai di imparare la Treccani a memoria... [F.d.A.]
On Thu, Jun 1, 2023 at 9:32 AM PG Doc comments form <noreply@postgresql.org> wrote:
The following documentation comment has been logged on the website:
Page: https://www.postgresql.org/docs/15/plpgsql-statements.html
Description:
Should be documented if this statement is allowed or not (if not, maybe set
as desired feature :-) )
EXECUTE format('update %I set col1=$1, col2=now() WHERE current of $3',
tabname)
USING myVal, myOpenCursor;
Well, you can handle this by naming the cursor specifically, based on the table that should be updated.
Then using the name of myOpenCursor.
and you use a refcursor variable to pass them around.
You name them like this, before opening them:
cCursor := 'my_cursor_update_table3';
Now usually the name matches the incoming variable name. You are going to have to play with this.
Later in your code, you can test the value of the cursor name by simply doing:
RAISE NOTICE 'Cursor Name: %', cCursor;
RAISE NOTICE 'Cursor Name: %', cCursor;
So you can copy it to a variable, and compare it. Then determine the table to apply the update to.
That's the best I can come up with...
Kirk Out!