is it possible to create a stored procedures on sql workbench that uses a redshift database ?
I tried to put in some procedure found on the internet like this one
CREATE OR REPLACE FUNCTION proc_sample RETURN INTEGER
IS
l_result INTEGER;
BEGIN
SELECT max(col1) INTO l_result FROM sometable;
RETURN l_result;
END;
but I get an error
the cursor is not located inside a statement
help please.
Here is my translation of your stored procedure for Redshift:
CREATE OR REPLACE PROCEDURE proc_sample (
l_result OUT INTEGER
)
LANGUAGE plpgsql
AS $$
BEGIN
SELECT max(col1) INTO l_result FROM sometable;
END
$$;
You call this stored procedure in Redshift as follows:
BEGIN; CALL proc_sample(); END;
-- l_result
-- ----------
-- 99
For more information see "Overview of stored procedures in Amazon Redshift"
you can not use from clause in function. you have to use procedure having parameter with out clause.
Related
create or replace procedure procedure_1()
language plpgsql
as $$
declare
precedure procedure_2()
begin
select 1;
end
begin
select 1;
end; $$
Is there any way to declare a procedure_2() inside procedure_1()?
Yes - if by "declare" you mean "create".
CREATE OR REPLACE PROCEDURE procedure_1(INOUT result int)
LANGUAGE plpgsql AS
$proc1$
BEGIN
CREATE OR REPLACE PROCEDURE procedure_2(INOUT result int)
LANGUAGE plpgsql AS
$proc2$
BEGIN
result := 2;
END
$proc2$;
result := 1;
END
$proc1$;
db<>fiddle here
You just have to get the quoting right. See:
What are '$$' used for in PL/pgSQL
Insert text with single quotes in PostgreSQL
Functions and procedures are not "declared", but "created" in Postgres. That creates an object in the database which is then visible and usable by all with appropriate permissions. (Not just a temporary object local to the procedure or transaction.)
You can, however, create a "temporary" function or procedure, with this "hack" - if that's what you had in mind:
How to create a temporary function in PostgreSQL?
I have created a stored procedure using PGADMIN4. Inside the SP, I have selected a view table. However, I want the data inside the stored procedure to be inserted into a new table. I have tried below code, but it is showing an error:
SP name: Test
New table name: Customer
Insert into public.Customer exec public.Test
This is my SP code:
create procedure test()
language plpgsql
as $$
BEGIN
Select * from public.customer_list;
END;
$$;
ERROR: syntax error at or near "exec"
Procedures cannot be used in SQL. If you must have a stored procedure (define as code stored in the database to be executed) then change to a SQL function. Which returns a type.
create function copy_customer_list()
returns setof customer_list
language sql
as $$
Select * from customer_list;
$$;
Then you can insert into other table with
insert into customer
select * from copy_customer_list();
I am implementing Row Level Security (RLS) on a postgres table. To use a single user, I am setting a configuaration_parameter for each session that maps to the row's identity and it works. I can test this using SQL but since I am using Mulesoft for the application, I don't have control over setting up connections and setting the parameter then. I tried to create a stored procedure where I try to set the value in the beginning but postgres doesn't like it. The docs don't share whether I can implement it in the SP or not so wondering if you guys know for sure so I can look at alternate solutions.
https://www.postgresql.org/docs/12/sql-set.html
The below does not work if I uncomment the line SET doc.provider=$1;
CREATE OR REPLACE PROCEDURE getParticipants(text)
LANGUAGE plpgsql
AS $$
BEGIN
--SET doc.provider=$1;
SELECT * FROM disclosure.participantsxref;
END;
$$;
Statement SET doesn't allow parametrization.Instead you can use a function set_config:
CREATE OR REPLACE FUNCTION foo(text)
RETURNS SETOF disclosure.participantsxref AS $$
BEGIN
PERFORM set_config('doc.provider', $1, true);
RETURN QUERY SELECT * FROM disclosure.participantsxref;
END $$
LANGUAGE plpgsql;
In your example, there is another issue - PostgreSQL's procedures cannot to returns tables - if you want to return table, then you have to use function. Functions can return tables with statement RETURN QUERY.
You can try to use dynamic SQL :
create or replace procedure myproc ()
as $$
begin
execute format('set lc_numeric=%L', 'fr_FR') ;
end;
$$
language 'plpgsql';
CREATE PROCEDURE
show lc_numeric;
lc_numeric
-------------
en_US.UTF-8
(1 row)
call myproc();
CALL
show lc_numeric;
lc_numeric
------------
fr_FR
(1 row)
I'm trying to store a simple SELECT query with the new CREATE PROCEDURE method in PostgreSQL 11. My idea is to store the queries in the DB, because I can have a much simple code in my API server and maybe I don't need to develop a query builder if I can use if/else in an sql function with enforced type safety. I have this minimal example:
First I tried this plpgsql function:
CREATE OR REPLACE PROCEDURE test_proc() AS $$
BEGIN
SELECT * FROM my_db
LIMIT 1;
END;
$$ LANGUAGE plpgsql;
CALL test_proc();
However throws this error:
ERROR: query has no destination for result data
HINT: If you want to discard the results of a SELECT, use PERFORM instead.
CONTEXT: PL/pgSQL function test_proc() line 3 at SQL statement SQL state: 42601
If I trying to use RETURN QUERY:
CREATE OR REPLACE PROCEDURE test_proc() AS $$
BEGIN
RETURN QUERY;
SELECT * FROM my_db
LIMIT 1;
END;
$$ LANGUAGE plpgsql;
I'm getting this error:
ERROR: cannot use RETURN QUERY in a non-SETOF function
LINE 17: RETURN QUERY; ^
SQL state: 42804
Character: 310
I'm also getting error when I try to use RETURNS void AS $$ or RETURNS table(...) AS $$. Seems like RETURNS not supported in CREATE PROCEDURE? So, is it possible to return a table with the new stored procedure method? Or if it's not, maybe JSON?
Procedures in PostgreSQL (Oracle, DB2) are not same like procedures in MS-SQL. It has different target, and you cannot use it. Usually, the best what you can do, forgot all what you know from MSSQL. The procedural part is really different.
Only functions can returns some data - so you need to use functions. Functions can returns scalar value, composite value or array value, or table. You want function that returns table.
CREATE OR REPLACE FUNCTION fx()
RETURNS SETOF mytab AS $$
BEGIN
RETURN QUERY SELECT * FROM mytab;
END
$$ LANGUAGE plpgsql;
SELECT * FROM fx();
For record:
You can use SQL function, that can have better (or worse) performance (depends on context). These functions are sometimes named as parametrized views.
CREATE OR REPLACE FUNCTION fx()
RETURNS SETOF mytab AS $$
SELECT * FROM mytab;
$$ LANGUAGE sql;
Attention: this technique is antipattern!!! Don't do it. It is really not good idea. The functions should not to wrap queries. If you want to hide some complexity of queries, then use a views. Don't use a functions. Functions are effective barier for query optimizer, and when you use this antipattern, then optimizer cannot to well optimize any non trivial queries that use in this form evaluated subqueries.
Use it - if you want very very slow applications - or if your data model or queries are primitive. In other cases, don't do it.
Don't afraid of SQL - it is great language designed for manual usage. It is good to place all data access to one module (model), to don't access database everywhere in your code, but it is bad too hide SQL in your code.
First of all Procedure was introduced in PostgreSQL 11, If you are using below 11th version, you cannot use Procedures. Instead to Procedure you can use functions.
Syntax to create function
CREATE or replace function function_name(_parameter varchar)
returns table(col1 varchar, col2 varchar, col3 varchar)
language 'plpgsql'
as $BODY$
BEGIN
return query select a.col1, a.col2, b.col3 from table a
join table2 as b on a.col1 = b.col1;
END;
$BODY$;
you can call a function same a like table
select * From function_name('sample data');
syntax to create Procedure.
CREATE OR REPLACE PROCEDURE procedure_name(_parameter varcar,INOUT result refcursor)
LANGUAGE 'plpgsql'
AS $BODY$
BEGIN
open result for SELECT , * from sampletable where a = _parameter;
END;
$BODY$;
you can execute a Procedure using call keyword, within a transaction
BEGIN;
CALL public.procedure_name( 'sample data', 'test');
fetch all in "test";
COMMIT;
The postgreSql 11. we have to create a stored procedure
there is the solution :
Create procedure to execute query in PostgreSQL
I would like to create a temp table in a stored procedure which has a STABLE volatility category setted to store the result of a select for later usage in the stored procedure. At the end of the stored procedure this temp table is deallocated and i am sure that this temp table does not have any affect on the database, because as far as i know with this volatility category i ensure the optimizer that this stored procedure will not affect the database.
So i would like to do something like this:
Create a stored procedure which returns with a query:
CREATE OR REPLACE FUNCTION storedproc()
RETURNS TABLE
(Egy TEXT,
Ketto TEXT)
AS $$
BEGIN
RETURN QUERY SELECT * FROM temptable;
END;
$$ LANGUAGE plpgsql;
Create a stored procedure which is using the previous query:
CREATE OR REPLACE FUNCTION stablefunction()
RETURNS TABLE
(Egy TEXT,
Ketto TEXT)
AS $$
BEGIN
-- I would like to store the results here for later usage
CREATE TEMP TABLE buba AS select * from storedproc();
-- Do other stuff
-- ...
-- Reuse the results here which was stored before
END;
$$ LANGUAGE plpgsql
STABLE;
But when i want to execute this stored procedure as this:
DO
$$
BEGIN
perform stablefunction() ;
END;
$$ LANGUAGE plpgsql;
i get the following error message:
ERROR: CREATE TABLE AS is not allowed in a non-volatile function
Maybe this is not the intended usage of the stored procedures, but then is there a way for store the result of a query inside of the stored procedure for later usage in the same stored procedure, maybe like a handle or somethings?
The documentation states clearly: A stable function cannot modify the database. A temporary table is a part of a database as well, so you cannot create it, insert into, delete from etc. Your concept seems a bit strange but I don't want to judge it. There is a trick that allows what you want to do. Perfom all actions on the temp table using other functions that do not have to be stable. Example:
create or replace function create_my_temp_table()
returns void language plpgsql volatile as $$
begin
create temp table temp_table(id int);
insert into temp_table values (123);
end $$;
create or replace function stable_function()
returns text language plpgsql stable as $$
begin
perform create_my_temp_table();
return 'ok';
end $$;
Test:
select stable_function();
stable_function
-------------
ok
(1 row)
select * from temp_table;
id
-----
123
(1 row)