Some one please help me on this problem. I'm using postgresql ver 12. Thank you. Please read the comment on the result. Running from function doesn't work. so weird.
-- NOT WORKING
CREATE OR REPLACE FUNCTION mefunc()
RETURNS TRIGGER AS $BODY$
DECLARE
a RECORD;
BEGIN
FOR a IN SELECT "aa" FROM medata LOOP
INSERT INTO othermedata ("id", "aa") VALUES ('1', a.aa);
END LOOP;
RETURN NEW;
END
$BODY$ LANGUAGE plpgsql;
when i raise notice the value of a i get ()
WORKING
DO $$
DECLARE
a RECORD;
BEGIN
FOR a IN SELECT "aa" FROM medata LOOP
INSERT INTO othermedata ("id", "aa") VALUES ('1', a.aa);
END LOOP;
END $$
When I raise notice the value of a I get output as "someoutputdata"
Try this. You should return new record when using Trigger. As you are not returning any value so it is returning null value. I have tested the below code and it is working fine.
CREATE OR REPLACE FUNCTION mefunc()
RETURNS TRIGGER AS $BODY$
DECLARE
a RECORD;
BEGIN
FOR a IN SELECT aa FROM metadata loop
INSERT INTO othermedata (id, aa) VALUES ('1', a.aa);
END LOOP;
RETURN new;
END
$BODY$ LANGUAGE plpgsql;
Related
I have the following function in a before insert trigger:
CREATE OR REPLACE FUNCTION schema.table_somefun()
RETURNS trigger AS
LANGUAGE 'plpgsql';
$BODY$
BEGIN
IF NEW.col2 NOT NULL THEN
NEW.col1 := CASE NEW.col1
WHEN '121432' THEN '321123'
ELSE <command> END CASE; --there should be a command aborting insertion without error or exception
END IF;
RETURN NEW;
END;
$BODY$
The ELSE statement should abort insertion. Is there a command which drops the query without telling it to the client and leaving the table untouched?
Just use
RETURN NULL;
instead of
RETURN NEW;
to cancel the INSERT for the row and do nothing instead.
But you cannot execute a PL/pgSQL statement inside an SQL CASE expression. (Don't confuse SQL CASE with the similar control structure CASE of PL/pgSQL!)
Could look like this:
CREATE OR REPLACE FUNCTION schema.table_somefun()
RETURNS trigger AS
$func$
BEGIN
IF NEW.col2 NOT NULL THEN
IF NEW.col1 = '121432' THEN -- could also be plpgsql CASE ...
NEW.col1 := '321123';
ELSE
RETURN NULL;
END IF;
END IF;
RETURN NEW;
END
$func$ LANGUAGE plpgsql;
I have made the following query which is working perfect by itself but when i call it inside trigger function i got problem.
select insert_new_grade('title0', return3_6(0), return3_6(1), return3_6(2), s.code)
FROM "student" as s
where find_st(s.grade)>=5;
insert_new_grade is a function that inserts a new row in a table every time it's being called.
Here is the trigger :
CREATE OR REPLACE FUNCTION insert_d()
RETURNS TRIGGER AS $$
BEGIN
select insert_new_grade('title0', return3_6(0), return3_6(1), return3_6(2), s.code)
FROM "student" as s
where find_st(s.grade)>=5;
return new;
END;
$$ LANGUAGE plpgsql;
and here is the insert function :
CREATE OR REPLACE FUNCTION insert_new_grade(title0 character(100), prof0 character(11), prof1 character(11))
RETURNS VOID AS $$
BEGIN
INSERT INTO "d_table"(thes0, title, grade, prof, secProf)
VALUES (null, title0, null, prof0, prof1);
END
$$
LANGUAGE 'plpgsql';
Is there a way to make the query work inside the trigger function ? If i use perform instead of select the insert function does not have result. I've read about cursors but I'm new in postgresql and I don't know how to do it. Any help ?
i modifited your trigger function:
check your trigger function in conlose pgAdmin, is visible raise info text
CREATE OR REPLACE FUNCTION insert_d()
RETURNS TRIGGER AS $$
declare
rec record;
BEGIN
for rec in (select * from student s where find_st(s.grade)>=5) loop
raise info 'LOOP code = %',rec.code;
PERFORM insert_new_grade('title0', return3_6(0), return3_6(1), return3_6(2), rec.code);
end loop;
return new;
END;
$$ LANGUAGE plpgsql;
I had this :
CREATE FUNCTION upsert_user(u_name text, u_fullname text, u_email text, u_suffix text) RETURNS integer
LANGUAGE plpgsql
AS $$
DECLARE
userid users.id_user%TYPE;
BEGIN
LOOP
-- first try to update
UPDATE users SET "fullname" = u_fullname, "email" = u_email, "suffix" = u_suffix WHERE "name" = u_name RETURNING "id_user" INTO userid;
-- check if the row is found
IF FOUND THEN
RETURN userid;
END IF;
-- not found so insert the row
BEGIN
INSERT INTO users ("name", "fullname", "email", "suffix") VALUES (u_name, u_fullname, u_email, u_suffix) RETURNING "id_user" INTO userid;
RETURN userid;
EXCEPTION WHEN unique_violation THEN
-- do nothing and loop
END;
END LOOP;
END;
$$;
CREATE TRIGGER link_entity
BEFORE INSERT
ON public.users
FOR EACH ROW
EXECUTE PROCEDURE public.link_entity();
CREATE FUNCTION link_entity() RETURNS trigger
LANGUAGE plpgsql
AS $$ DECLARE
entityid integer;
BEGIN
INSERT INTO privileges_entities (name) VALUES (NEW.name) RETURNING privileges_entities.id_entity INTO entityid;
IF NOT FOUND THEN
RETURN NULL;
END IF;
NEW.ref_entity := entityid;
RETURN NEW;
END;
$$;
After updated postgresql to version 9.5, I modified the function upsert_user to use the new instruction ON CONFLICT:
CREATE FUNCTION upsert_user(u_name text, u_fullname text, u_email text, u_suffix text) RETURNS integer
LANGUAGE sql
AS $$
INSERT INTO users (name, fullname, email, suffix)
VALUES (u_name, u_fullname, u_email, u_suffix)
ON CONFLICT (name) DO UPDATE SET name=EXCLUDED.name, fullname=EXCLUDED.fullname, email=EXCLUDED.email, suffix=EXCLUDED.suffix
RETURNING id_user;
$$;
The problem is that, now, new rows are inserted in the privileges_entities table even if insertion into the users table fails.
Is it possible to rollback the trigger if the insertion of the user leads to a conflict?
This is indeed a side-effect of using the new ON CONFLICT clause.
My solution here would be to add a check into the link_entity() function itself and prevent it from continuing if the user already exists. Like this:
CREATE FUNCTION link_entity() RETURNS trigger
LANGUAGE plpgsql
AS $$ DECLARE
entityid integer;
nameExists boolean;
BEGIN
EXECUTE format('SELECT EXISTS(SELECT 1 FROM %I.%I WHERE name = NEW.name)', TG_TABLE_SCHEMA, TG_TABLE_NAME) INTO nameExists;
IF nameExists THEN
RETURN NEW; -- just return, entity already linked
END IF;
INSERT INTO privileges_entities (name) VALUES (NEW.name) RETURNING privileges_entities.id_entity INTO entityid;
IF NOT FOUND THEN
RETURN NULL;
END IF;
NEW.ref_entity := entityid;
RETURN NEW;
END;
$$;
I want to test results of a Postgres function (changing the function is not a possibility).
The function receives as arguments a REFCURSOR and several other things and returns the same RECURSOR.
get_function_that_returns_cursor(ret, 4100, 'SOMETHING', 123465)
Now I want to create a small test in Postgres to get the results of this FUNCTION.
Something Like the code below (this is my approach but it is not working):
DO $$ DECLARE
ret REFCURSOR;
row_to_read table_it_will_return%ROWTYPE ;
BEGIN
PERFORM get_function_that_returns_cursor(ret, 4100, 'SOMETHING', 123465);
-- OR SELECT get_function_that_returns_cursor(ret, 4100, 'SOMETHING', 123465) INTO ret
FOR row_to_read IN SELECT * FROM ret LOOP
-- (...)
RAISE NOTICE 'Row read...';
END LOOP;
CLOSE ret;
END $$;
Any suggestion on how to get this to work? A generic solution that can be used for testing this type of functions (that get a Cursor and return a Cursor?
And if we don't know the rowtype that is being returned how could we do it?
Q1
Your "small test" can be plain SQL:
BEGIN;
SELECT get_function_that_returns_cursor('ret', 4100, 'foo', 123); -- note: 'ret'
FETCH ALL IN ret; -- works for any rowtype
COMMIT; -- or ROLLBACK;
Execute COMMIT / ROLLBACK after you inspected the results. Most clients only display the result of the lat command.
More in the chapter Returning Cursors of the manual.
Q2
And if we don't know the rowtype that is being returned how could we do it?
Since you only want to inspect the results, you could cast the whole record to text.
This way you avoid the problem with dynamic return types for the function altogether.
Consider this demo:
CREATE TABLE a (a_id int PRIMARY KEY, a text);
INSERT INTO a VALUES (1, 'foo'), (2, 'bar');
CREATE OR REPLACE FUNCTION reffunc(INOUT ret refcursor)
LANGUAGE plpgsql AS
$func$
BEGIN
OPEN ret FOR SELECT * FROM a;
END
$func$;
CREATE OR REPLACE FUNCTION ctest()
RETURNS SETOF text
LANGUAGE plpgsql AS
$func$
DECLARE
curs1 refcursor;
rec record;
BEGIN
curs1 := reffunc('ret'); -- simple assignment
LOOP
FETCH curs1 INTO rec;
EXIT WHEN NOT FOUND; -- note the placement!
RETURN NEXT rec::text;
END LOOP;
END
$func$;
db<>fiddle here
Old sqlfiddle
This worked for what I wanted:
DO $$ DECLARE
mycursor REFCURSOR;
rec RECORD;
BEGIN
SELECT 'ret' INTO mycursor FROM get_function_that_returns_cursor('ret'::REFCURSOR, 4100, 'SOMETHING', 123465);
WHILE (FOUND) LOOP
FETCH mycursor INTO rec;
RAISE NOTICE 'Row read. Data: % ', rec.collumn_name;
END LOOP;
END $$
I have a trigger function I'm trying to have execute in Postgres.
It compiles and adds the trigger, however it does not insert the value into the table as I had hoped.
The function it uses looks like this:
CREATE OR REPLACE FUNCTION
calc_gnpDifference(n integer, o integer)
RETURNS NUMERIC AS $$
SELECT $1 ::numeric - $2::numeric AS gnpDifference;
$$ LANGUAGE SQL;
And the Trigger part:
CREATE OR REPLACE FUNCTION autoCalculate() RETURNS TRIGGER AS $$
BEGIN
IF NEW.gnp_old > NEW.gnp_old THEN
NEW.gnpDifference := calc_gnpDifference(NEW.gnp_old, NEW.gnp);
END IF;
RETURN NEW;
END;
$$ LANGUAGE plpgsql;
DROP TRIGGER insertDifference ON country;
CREATE TRIGGER insertDifference BEFORE INSERT ON country
FOR EACH ROW EXECUTE PROCEDURE autoCalculate();
However, when I insert data, the trigger does not update the gnpDifference field as I had hoped. Thoughts on why this might be happening?
Obviously this condition: IF NEW.gnp_old > NEW.gnp_old will never be true so the trigger will never have any effect.