How to create procedure and call/Execute in PostgreSQL
To return a result "table", use a function not a procedure:
create function Proc_StudentLogin(Sid bigint)
returns setof students
as
$Body$
select * from students where id = sid;
$Body$
language sql
stable;
-- Use function:
select *
from Proc_StudentLogin(1);
--Create Procedure
Create procedure Proc_StudentLogin(
Sid bigint,
inout get_result refcursor)
Language 'plpgsql'
AS $Body$
Begin
open get_result for
Select * from Students where id = sid;
End
$Body$;
--Call procedure
Call Proc_StudentLogin(1,'result');
fetch all in "result";
Related
May I ask on how to call a method when the content of the stored procedure is about select statement? (Using postgreSQL)
CREATE OR REPLACE PROCEDURE select_table(table_name VARCHAR(255))
language plpgsql
as $$
BEGIN
EXECUTE('SELECT * FROM' || ' ' || quote_ident(table_name));
END $$;
CALL select_table('employee_table');
EDITED(USING FUNCTION)
CREATE OR REPLACE FUNCTION select_table(table_name VARCHAR(255))
language plpgsql
as $$
BEGIN
SELECT * FROM table_name
RETURN table_name;
END $$;
In PostgreSQL procedures doesn't execute any select statements and doesn't have return.
For returning data you can use functions. But functions also cannot return different structural data, examples:
CREATE OR REPLACE FUNCTION fr_test()
RETURNS TABLE(id integer, bookname character varying)
LANGUAGE plpgsql
AS $function$
begin
return QUERY
SELECT tb.id, tb.bookname from rbac.books tb;
end;
$function$
;
or
CREATE OR REPLACE FUNCTION fr_test()
RETURNS setof public.books
LANGUAGE plpgsql
AS $function$
begin
return QUERY
SELECT * from public.books;
end;
$function$
;
But for returning difference tables you can do it using procedures and using out refcursor, like as in Oracle. For example:
create or replace procedure pr_test(OUT r1 refcursor)
as $$
begin
open r1 for
select * from public.books;
end;
$$ language plpgsql;
I want to return the whole table with stored procedure not function
my code is:
CREATE OR REPLACE PROCEDURE public.test()
RETURN TABLE (
id numeric
, test varchar
) AS -- Results -- remove this
$func$
BEGIN
RETURN QUERY
SELECT *
FROM public.test
END
$func$ LANGUAGE plpgsql;
but its not works.
Stored procedures aren't meant to return anything, use a function. And you don't need PL/pgSQL for that either:
create or replace FUNCTION public.test()
returns TABLE (id numeric, test varchar)
AS
$func$
SELECT *
FROM public.test;
$func$
LANGUAGE sql;
As you return all columns of one table, you can also use returns setof
create or replace FUNCTION public.test()
returns setof public.test
AS
$func$
SELECT *
FROM public.test;
$func$
LANGUAGE sql;
Then use it like a table:
select *
from test();
I'm new to postgresql, i have a procedure block this is working but i dont see any table or column, what this problem.
CREATE PROCEDURE list3(
)
LANGUAGE sql
AS $$
select * from stok
$$;
call list3()
Functions return values.
Example:
create table table_example(col1 varchar(100),col2 int);
CREATE OR REPLACE FUNCTION get_table_example()
RETURNS TABLE (
l_col1 VARCHAR,
l_col2 INT
)
LANGUAGE plpgsql
AS $$
BEGIN
RETURN QUERY
SELECT *
FROM table_example;
END;
$$
select * from get_table_example();
I have this postgresql function
CREATE OR REPLACE FUNCTION sp_select_test(_id bigint)
RETURNS void AS
$BODY$
BEGIN
copy (select sub.id
from (
SELECT id FROM sim s where id = _id) sub) TO '/tmp/results.tsv';
END;
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;
ALTER FUNCTION sp_select_test(bigint)
OWNER TO postgres;
When I run
select * from sp_select_test(264);
I get error - column "_id" does not exist
If I replace the variable _id in the function with a value say 264, the function works. That is if instead of id = _id I use id = 264
Any reason why the function is failing?
CREATE OR REPLACE FUNCTION sp_select_test(_id bigint)
RETURNS void AS
$BODY$
BEGIN
execute $$copy (select sub.id
from (
SELECT id FROM sim s where id = $$||_id||$$) sub) TO '/tmp/results.tsv'$$;
END;
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;
ALTER FUNCTION sp_select_test(bigint)
OWNER TO postgres;
I have the function below...
CREATE OR REPLACE FUNCTION class_listing(var_sem integer, var_sy character) RETURNS SETOF RECORD AS
DECLARE
current_offering record;
BEGIN
SELECT subcode, offerno INTO current_offering FROM offering WHERE SY=var_sem AND SEM=var_sy;
END;
How to return current_offering as resultset?
You can use a SQL or PLpgSQL functions. Using anonymous records as returning type is not practical (mainly it is not friendly, when you write queries). Use RETURNS TABLE or OUT parameters instead.
CREATE OR REPLACE FUNCTION class_listing(var_sem integer, var_sy varchar)
RETURNS TABLE (subcode varchar, offerno int) AS $$
BEGIN
RETURN QUERY SELECT o.subcode, o.offerno
FROM offering
WHERE SY=var_sem AND SEM=var_sy;
END;
$$ LANGUAGE plpgsql;
or SQL language
CREATE OR REPLACE FUNCTION class_listing(var_sem integer, var_sy varchar)
RETURNS TABLE (subcode varchar, offerno int) AS $$
SELECT o.subcode, o.offerno
FROM offering
WHERE SY=$1 AND SEM=$2;
$$ LANGUAGE sql;
Attentions - query based functions works (with small exception) as optimizer barrier. So be careful when you use it in complex queries.
For completeness - your example can be written as:
CREATE OR REPLACE FUNCTION class_listing(var_sem integer, var_sy varchar)
RETURNS SETOF RECORD AS $$
DECLARE current_offering record;
BEGIN
FOR current_offering IN
SELECT o.subcode, o.offerno
FROM offering
WHERE SY=var_sem AND SEM=var_sy;
LOOP
RETURN NEXT current_offering;
END LOOP;
RETURN;
END;
$$ LANGUAGE plpgsql;
But this form is deprecated now