Re: psql - user defined SQL variables

Hi,

Am Mi, den 18.08.2004 schrieb Grainne Reilly um 6:22:
> I am new to PostgreSQL and am porting some scripts written for MySQL over
> to psql.  There is one MySQL feature which I cannot find in psql - user
> defined SQL variables. In MySQL I can use these to hold the result
> (numeric, string or null) of a select: e.g.
> select @count = count(*) from mytable;
> The @count variable now holds the result of that select, and I can use it
> in where clauses, updates, inserts  etc.
> I checked out the \set psql variable but I haven't found a way to tweak it
> to give me the result of a sql statement - is there any way to do that (I'm
> using PostgreSQL version 7.4.3)?
> Thanks in advance for any suggestions,
> Grainne.

Postgres supports subselects (for update and stuff) and you can insert
like that:

INSERT INTO foo (a,b,c) SELECT a,b,c FROM ...

If thats not enough, you have a bounch of pl/*
languages to write sophisticated procedures
in the database where you have variables for
single values as well as recordsets.

Regards
Tino Wildenhain