I'm trying to mark a boolean column on a different table to true upon the insertion of a matching record.
Here's what I've got:
CREATE or replace FUNCTION mark_as_sold() RETURNS trigger AS
$BODY$
BEGIN
UPDATE listing
set listing.sold = true;
WHERE listing.id = NEW.listing_id;
RETURN NEW;
END
$BODY$
LANGUAGE plpgsql;
CREATE TRIGGER update_child_after_update
AFTER INSERT
ON transaction
FOR EACH ROW
EXECUTE PROCEDURE mark_as_sold();
When I create a record on the transaction table, nothing happens. I'm stumped. Any help is greatly appreciated.
I figured it out. I was messing up my relations. Here's the proper code:
CREATE OR REPLACE FUNCTION mark_as_sold()
RETURNS TRIGGER
AS $$
BEGIN
UPDATE listing
set sold = true
WHERE listing.id = NEW.listing_id;
RETURN NEW;
RETURN NEW;
END;
$$
LANGUAGE plpgsql;
CREATE TRIGGER test_trigger BEFORE INSERT OR UPDATE
ON "transaction"
FOR EACH ROW EXECUTE PROCEDURE mark_as_sold();
Related
Here is my trigger function
CREATE OR REPLACE FUNCTION test_table_insert()
RETURNS TRIGGER
AS $$
BEGIN
IF NEW.id IS NULL THEN
RAISE EXCEPTION 'id is null';
END IF;
UPDATE e_sub_agreement SET ro_id = NEW.id WHERE id = NEW.id;
RETURN NEW;
END;
$$
LANGUAGE plpgsql;
CREATE TRIGGER test_table_insert AFTER INSERT ON e_sub_agreement FOR EACH ROW EXECUTE PROCEDURE test_table_insert();
The problem is that it doesn't update table e_sub_agreement. I checked NEW value and everything is good. It returns with the new id. If I change where statement id = "some existing id in table", then it works. It changes ro_id to the new id. How is it possible? My guess is that data has not been inserted into table and trigger function can't find row with the given id. But it's not how trigger's after insert function works. What's the magic?
An AFTER trigger can not change anything. Running an additional UPDATE is also quite inefficient. Change this to a BEFORE trigger and assign the value you want:
CREATE OR REPLACE FUNCTION test_table_insert()
RETURNS TRIGGER
AS $$
BEGIN
IF NEW.id IS NULL THEN
RAISE EXCEPTION 'id is null';
END IF;
NEW.ro_id := NEW.id;
RETURN NEW;
END;
$$
LANGUAGE plpgsql;
CREATE TRIGGER test_table_insert
BEFORE INSERT ON e_sub_agreement
FOR EACH ROW EXECUTE PROCEDURE test_table_insert();
Note that the NOT NULL check is better done by defining the column as NOT NULL.
I have a table in PostgretSQL. I want to build a trigger that avoids to update colb1 column. This column has five alternatives: Rea, Can, Loa, Mul, Alm. So the trigger doesn't let upload values from Rea to Can.
I've built this function but this is fail.
CREATE OR REPLACE FUNCTION example_trigger()
RETURNS trigger AS
$BODY$
BEGIN
new.colb1.tabl1 = 'Rea' := old.colb1.tabl1 = 'Can';
new.colb1.tabl1 = 'Can' := old.colb1.tabl1 = 'Rea';
RETURN new;
END
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;
DROP TRIGGER IF EXISTS trigger_name ON table1;
CREATE TRIGGER trigger_name BEFORE UPDATE ON table1
FOR EACH ROW EXECUTE PROCEDURE example_trigger();
I edited my post with changes:
CREATE OR REPLACE FUNCTION example_trigger()
RETURNS TRIGGER AS
$$
BEGIN
NEW.colb1 := OLD.colb1;
RETURN NEW;
END;
$$ LANGUAGE plpgsql;
CREATE TRIGGER not_changes
BEFORE UPDATE
ON tabl1
FOR EACH ROW
EXECUTE PROCEDURE example_trigger();
It's not exactly that I want because I want that the values Loa, Mul and Alm can be update.
A slight modification of your function to stop the modification of colb1 from Rea or Can to Can or Rea.
CREATE OR REPLACE FUNCTION example_trigger()
RETURNS TRIGGER AS
$$
BEGIN
IF OLD.colb1 in ('Rea', Can') AND NEW.colb1 IN ('Rea', 'Can') THEN
NEW.colb1 := OLD.colb1;
END IF;
RETURN NEW;
END;
$$ LANGUAGE plpgsql;
This will not stop a user from using an intermediate UPDATE to change to one of Loa/Mul/Alm and then to either Rea or Can
I have an issue regarding a Triggers with PostgreSQL 10. Here is the situation.
I have a table called index_name which contain à column named index_ref. Into this field I have created a list of value as example: PBM PI, PBM PO, etc.
I would like to use this table to store valid name as reference for another table called gis_osm_places.
So, whenever someone try to insert a value not into the list then an exception message will pop-up to say: NOT ALLOWED COMMIT. PLEASE USE: (reference list)
Here are my tables:
Here is where I am with the trigger:
CREATE FUNCTION public.check_column_value()
RETURNS trigger
LANGUAGE 'plpgsql'
COST 100
VOLATILE NOT LEAKPROOF
AS $BODY$
DECLARE
ref_allowed character varying;
BEGIN
IF TG_OP = 'INSERT' OR TG_OP = 'UPDATE'
THEN
IF NEW.index_a is not null OR NEW.index_a NOT IN (SELECT index_ref from public.index_name)
THEN
ref_allowed := (SELECT string_agg(index_ref,',') from public.index_name);
RAISE EXCEPTION 'NOT ALLOWED COMMIT. PLEASE USE : %',ref_allowed;
END IF;
RETURN NEW;
END IF;
END;
$BODY$;
ALTER FUNCTION public.check_column_value()
OWNER TO "postgres";
CREATE TRIGGER check_column_value
BEFORE INSERT
ON public.gis_osm_places
FOR EACH ROW
EXECUTE PROCEDURE public.check_column_value();
Actually nothing is happening, I mean I can add whatever I want without an error.
Any idea or upgrade of the code would be greatly appreciate.
Thanks in advance !
You do not need not and do not want a trigger for this. This functionality is build in. Just create a Foreign Key constraint on gis_osm_places referencing index_name.
alter table gis_osm_places
add constraint osm_places2index_fk
foreign key (index_a)
references index_name(index_ref);
Now drop your trigger and the trigger function. The downside being you do not get the message you have created. But you handle that in your exception processing in the your app.
I finally found what went wrong !
CREATE FUNCTION public.check_column_value()
RETURNS trigger
LANGUAGE 'plpgsql'
COST 100
VOLATILE NOT LEAKPROOF
AS $BODY$
DECLARE
ref_allowed character varying;
BEGIN
IF TG_OP = 'INSERT' OR TG_OP = 'UPDATE'
THEN
IF NEW.index_a is not null AND NEW.index_a NOT IN (SELECT index_ref from public.index_name)
THEN
ref_allowed := (SELECT string_agg(index_ref,',') from public.index_name);
RAISE EXCEPTION 'NOT ALLOWED COMMIT. PLEASE USE : %',ref_allowed;
END IF;
RETURN NEW;
END IF;
END;
$BODY$;
ALTER FUNCTION public.check_column_value()
OWNER TO "postgres";
CREATE TRIGGER check_column_value
BEFORE INSERT OR UPDATE
ON public.gis_osm_places
FOR EACH ROW
EXECUTE PROCEDURE public.check_column_value();
I'm trying to create a trigger with a condition. Based on the geom length I want the attribute "nom" (= name) to be written in upper case or lower case.
here's what I have:
CREATE OR REPLACE FUNCTION public.test_upper_lower()
RETURNS trigger AS
$BODY$
BEGIN
NEW.dummy:= (ST_Length(new.geom));
if (SELECT dummy FROM ligne_ligne)>100
then NEW.nom:= LOWER(nom) FROM ligne_ligne;
else NEW.nom:= UPPER(nom) FROM ligne_ligne;
end if;
RETURN NEW;
END;
$BODY$
LANGUAGE plpgsql;
DROP trigger IF EXISTS test_upper_lower on public.ligne_ligne;
CREATE trigger test_upper_lower BEFORE INSERT OR UPDATE on public.ligne_ligne
FOR EACH ROW
EXECUTE PROCEDURE public.test_upper_lower();
With this I have a "more than one row returned by a subquery" error
Based on other questions on this forum I tried it using case instead of if and using when in the trigger itself not the function but neither are working
Any ideas ?
Thanks
You don't need (or can actually) use SELECT statements to access data from the inserted row.
The part SELECT dummy FROM ligne_ligne returns all rows from that table - not just from the one relevant to the trigger.
As you just want to check the value you just calculated, simply use new.dummy at that point:
CREATE OR REPLACE FUNCTION public.test_upper_lower()
RETURNS trigger AS
$BODY$
BEGIN
NEW.dummy:= ST_Length(new.geom);
if new.dummy > 100 then --<< no SELECT necessary
NEW.nom:= LOWER(new.nom); --<< no "FROM", just access the value
else
NEW.nom:= UPPER(new.nom);
end if;
RETURN NEW;
END;
$BODY$
LANGUAGE plpgsql;
I want to create a trigger so that whenever I make a change (Update or Delete) it should copy the old data to a new table (with same template).
I tried this code:
create table restrictions(ID int,name text);
insert into restrictions values(122,'suresh');
select * from restrictions;
create table restrictions_deleted(ID int,name text);// this is my duplicate table for keeping information of all updations.
CREATE OR REPLACE FUNCTION moveDeleted() RETURNS trigger AS $$
BEGIN
INSERT INTO restrictions_deleted VALUES(OLD.ID, OLD.name);
RETURN OLD;
END;
$$ LANGUAGE plpgsql;
CREATE OR REPLACE TRIGGER moveDeleted
BEFORE DELETE ON restrictions
FOR EACH ROW
EXECUTE PROCEDURE moveDeleted();
delete from restrictions where ID=122;
select * from restrictions_deleted;
This code is capable of recording all the deleted data into duplicate table. But I want to do same for updates also.
Any suggestion, any idea?
First - in a trigger function you need to RETURN NEW; instead of RETURN OLD;.
Second - change the trigger to BEFORE DELETE OR UPDATE.
Last - it is better to have AFTER DELETE OR UPDATE for a logging trigger. This way it wont do useless work, when the change is rolled back.
BTW here is a good example of logging/audit trigger.
UPDATE:
The function will look like:
CREATE OR REPLACE FUNCTION moveDeleted() RETURNS trigger AS $$
BEGIN
IF (TG_OP = 'UPDATE') THEN
INSERT INTO restrictions_deleted VALUES(OLD.ID, OLD.name);
RETURN NEW;
ELSIF (TG_OP = 'DELETE') THEN
INSERT INTO restrictions_deleted VALUES(OLD.ID, OLD.name);
RETURN OLD;
END IF;
END;
$$ LANGUAGE plpgsql;