Pass a SELECT result as an argument to postgreSQL function

Question

I have a table "UserState" with following fields: id, userid, ctime, state, endtime. I have a simple query:

SELECT userid FROM "UserState" WHERE ctime>'2014-07-14'::timestamp 

AND I have a plpgsql function, which must take the result of this query as an argument:

get_timeinstate(SELECT userid FROM "UserState" WHERE ctime>'2014-07-14'::timestamp); 

How to create function correctly to pass a query result as parametr there? It's necessery to understand, that the function returns another SQL result and I need to use there "IN" condition:

$func$ BEGIN  RETURN QUERY  SELECT  ...myanotherquery...  WHERE "UserState".userid IN (HERE I NEED TO INSERT MY QUERY RESULT) END; $func$ 

Answer 1

Pass the returned user_id set as array. Create the function to accept an integer array

create function get_timeinstate (     user_id_set integer[],     another_param... 

Then call it passing the array generated by array_agg

get_timeinstate(     (         select array_agg(userid)         from "UserState"         where ctime>'2014-07-14'::timestamp     ),     another_param ); 

Inside the function:

where "UserState".userid = any (user_id_set) 

BTW if you are using plpgsql you can place the query inside the function and pass just the date:

create function get_timeinstate (     p_ctime timestamp,     another_param... $func$ declare     user_id_set integer[] := (         select array_agg(userid)         from "UserState"         where ctime > p_ctime     ); begin     return query     select      ...myanotherquery...     where "UserState".userid = any (user_id_set) end; $func$ 

Answer 2

Just enclose in round brackets:

get_timeinstate(   (     SELECT userid FROM "UserState" WHERE ctime>'2014-07-14'::timestamp   ) );