Re: Escaping ' in a function

thank you thank you thank you thank you thank you. I can feel my hair
growing back already.

Patrick Hatcher
Macys.Com

Josh Berkus
<josh(at)agliodbs To: "Patrick Hatcher" <PHatcher(at)macys(dot)com>, pgsql-novice(at)postgresql(dot)org
.com> cc:
Subject: Re: [NOVICE] Escaping ' in a function
08/27/2002
04:13 PM
Please respond
to josh

Patrick,

> I'm trying to create a function that passes a string that will need to be
> quoted. I finally figured out how many single quotes I needed and as a
> test, I've shown it in v_sql. However, I now need to do the same thing
for
> my FOR...LOOP query.

Ah, the classic qouted-quoted-quoted string problem.

Here's what I sometimes do for these procedures:

1. Build the procedure, without doubling any quotes.
2. Use search-and-replace on just the string value to double those quotes.
3. Use seach-and-replace on the whole procedure to double all quotes.

I find that this is more likely to yield me the correct number of quotes.

> CREATE or REPLACE FUNCTION recompileview(varchar) RETURNS varchar AS '
>
> DECLARE
> tblname ALIAS FOR $1;
> old_view RECORD;
> v_sql varchar;
>
> begin
> /* This is what I need */
> v_sql := ''Select * from pg_views where definition ~* '''''' || tblname
||
> '''''''' ;
>
> FOR old_view in Select * from pg_views where definition ~*
> ''''tblname'''''' LOOP

Use:
FOR old_view IN SELECT * FROM pg_views WHERE definition ~* tblname LOOP

No quotes are necessary with this version

Or:
FOR old_view IN EXECUTE v_sql LOOP

BTW, this procedure is going to cause havoc if you have views referencing
other views. They won't necessarily be re-created in order.

--
-Josh Berkus
Aglio Database Solutions
San Francisco