Pass multiple values in single parameter - sql

Question

I want to call a function by passing multiple values on single parameter, like this:
SELECT * FROM jobTitle('270,378');
Here is my function.
CREATE OR REPLACE FUNCTION test(int)
RETURNS TABLE (job_id int, job_reference int, job_job_title text
, job_status text) AS
$$
BEGIN
RETURN QUERY
select jobs.id,jobs.reference, jobs.job_title,
ltrim(substring(jobs.status,3,char_length(jobs.status))) as status
FROM jobs ,company c
WHERE jobs."DeleteFlag" = '0'
and c.id= jobs.id and c.DeleteFlag = '0' and c.active = '1'
and (jobs.id = $1 or -1 = $1)
order by jobs.job_title;
END;
$$ LANGUAGE plpgsql;
Can someone help with the syntax? Or even provide sample code?

Answer 1

VARIADIC
Like #mu provided, VARIADIC is your friend. One more important detail:
You can also call a function using a VARIADIC parameter with an array type directly. Add the key word VARIADIC in the function call:
SELECT * FROM f_test(VARIADIC '{1, 2, 3}'::int[]);
is equivalent to:
SELECT * FROM f_test(1, 2, 3);
Other advice
In Postgres 9.1 or later right() with a negative length is faster and simpler to trim leading characters from a string:
right(j.status, -2)
is equivalent to:
substring(j.status, 3, char_length(jobs.status))
You have j."DeleteFlag" as well as j.DeleteFlag (without double quotes) in your query. This is probably incorrect. See:
PostgreSQL Error: Relation already exists
"DeleteFlag" = '0' indicates another problem. Unlike other RDBMS, Postgres properly supports the boolean data type. If the flag holds boolean data (true / false / NULL) use the boolean type. A character type like text would be inappropriate / inefficient.
Proper function
You don't need PL/pgSQL here. You can use a simpler SQL function:
CREATE OR REPLACE FUNCTION f_test(VARIADIC int[])
RETURNS TABLE (id int, reference int, job_title text, status text)
LANGUAGE sql AS
$func$
SELECT j.id, j.reference, j.job_title
, ltrim(right(j.status, -2)) AS status
FROM company c
JOIN job j USING (id)
WHERE c.active
AND NOT c.delete_flag
AND NOT j.delete_flag
AND (j.id = ANY($1) OR '{-1}'::int[] = $1)
ORDER BY j.job_title
$func$;
db<>fiddle here
Old sqlfiddle

Answer 2

Don't do strange and horrible things like converting a list of integers to a CSV string, this:
jobTitle('270,378')
is not what you want. You want to say things like this:
jobTitle(270, 378)
jobTitle(array[270, 378])
If you're going to be calling jobTitle by hand then a variadic function would probably be easiest to work with:
create or replace function jobTitle(variadic int[])
returns table (...) as $$
-- $1 will be an array if integers in here so UNNEST, IN, ANY, ... as needed
Then you can jobTitle(6), jobTitle(6, 11), jobTitle(6, 11, 23, 42), ... as needed.
If you're going to be building the jobTitle arguments in SQL then the explicit-array version would probably be easier to work with:
create or replace function jobTitle(int[])
returns table (...) as $$
-- $1 will be an array if integers in here so UNNEST, IN, ANY, ... as needed
Then you could jobTitle(array[6]), jobTitle(array[6, 11]), ... as needed and you could use all the usual array operators and functions to build argument lists for jobTitle.
I'll leave the function's internals as an exercise for the reader.