Oh wow folks! I totally misunderstood the docs then. (I also tried to Read The Manual before I posted here, too :blush:)
I must admit, I did try doing something like you suggested Erik. I tried things like:
DO $$
DECLARE
v_application_id uuid;
BEGIN
SELECT application_id INTO v_application_id FROM applications WHERE code = 'pg-test-cc';
SELECT * FROM application_foo WHERE application_id = v_application_id;
-- more SELECT * FROM child tables....
END $$;
but that never worked, with warning:
ERROR: query has no destination for result data HINT: If you want to discard the results of a SELECT, use PERFORM instead. CONTEXT: PL/pgSQL function inline_code_block line 7 at SQL statement SQL state: 42601
Which is why i (incorrectly?) thought this cannot be done?
So is there another trick to doing this instead? Is it maybe via the v_record "record" variable instead?
-JA-
> On 03/05/2023 14:25 CEST J.A. <postgresql@world-domination.com.au> wrote:
>
> ms-sql person here migrating over to pgsql. One of the first thing's I noticed
> with pgsql (or more specifically, PL/pgSQL) is that it doesn't support
> "variables" in a query?
>
> for example, here's some T-SQL:
>
> DECLARE @fkId INTEGER
>
> SELECT @fkId = fkId FROM SomeTable WHERE id = 1
>
> -- and then do something with that value..
>
> SELECT * FROM AnotherTable WHERE Id = @fkId
> SELECT * FROM YetAnotherTable WHERE FKId = @fkId
> -- etc..
plpgsql does support variable declarations [0] but does not use any special
notation like T-SQL. An equivalent to your example would be:
DO $$
DECLARE
v_fkid int;
v_rec record;
BEGIN
SELECT fkid INTO v_fkid FROM SomeTable WHERE id = 1;
SELECT * INTO v_rec FROM AnotherTable WHERE Id = v_fkid;
-- Do something with v_rec ...
END $$;
Prefixing variable names with v_ is just a convention to avoid ambiguous column
references (assuming that column names are not prefixed with v_) [1].
[0] https://www.postgresql.org/docs/current/plpgsql-declarations.html
[1] https://www.postgresql.org/docs/current/plpgsql-implementation.html#PLPGSQL-VAR-SUBST
--
Erik