I need to update the vat_total_sum of goods in a record using a trigger. But the trigger fires to update the record and falls into recursion. How can I avoid this?
The code:
CREATE OR REPLACE FUNCTION vat_total_sum() RETURNS TRIGGER AS $$
BEGIN
UPDATE goods SET vat_total_sum = NEW.vat_sum / 100 * NEW.vat_percent
WHERE goods_id = new.goods_id;
RETURN NEW;
END;
$$ LANGUAGE plpgsql;
CREATE TRIGGER vat_total_sum AFTER INSERT OR UPDATE ON goods
FOR EACH ROW EXECUTE PROCEDURE vat_total_sum();
Don't use UPDATE, use a BEFORE triger and assign the new value:
CREATE OR REPLACE FUNCTION vat_total_sum() RETURNS TRIGGER AS $$
BEGIN
new.vat_total_sum := NEW.vat_sum / 100 * NEW.vat_percent;
RETURN NEW;
END;
$$ LANGUAGE plpgsql;
CREATE TRIGGER vat_total_sum
BEFORE INSERT OR UPDATE ON goods
FOR EACH ROW EXECUTE PROCEDURE vat_total_sum();
Related
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'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();
I have written this function and this trigger:
CREATE OR REPLACE FUNCTION test4() RETURNS TRIGGER AS $BODY$
BEGIN
UPDATE "cf"
SET vol=(area*alt);
RETURN null;
END;
$BODY$
LANGUAGE plpgsql
trigger
CREATE TRIGGER trig_upd
AFTER OR UPDATE ON "cf"
FOR EACH ROW
EXECUTE PROCEDURE test4();
I have tested my function and it's ok. So I created the trigger, but I can't insert any value in the table "cf" because the system crashes.
If you want to update the value of vol for each modified row, don't use update, just assign the value. For this to work you also need to define the trigger as a before trigger:
CREATE OR REPLACE FUNCTION test4() RETURNS TRIGGER
AS
$BODY$
BEGIN
new.vol := new.area * new.alt;
RETURN new;
END;
$BODY$
LANGUAGE plpgsql;
CREATE TRIGGER trig_upd
BEFORE UPDATE ON "cf" --<< note the BEFORE!
FOR EACH ROW
EXECUTE PROCEDURE test4()
I want to write trigger to update table when new row is insert. I am using updatea Query like
UPDATE table SET
geom = ST_SetSRID(ST_MakePoint(longitude, latitude), 4326)
You need to use a BEFORE trigger and then assign the new value:
CREATE OR REPLACE FUNCTION function_update()
RETURNS trigger AS
$BODY$
BEGIN
new.geom := ST_SetSRID(ST_MakePoint(new.longitude, new.latitude), 4326);
RETURN new;
END;
$BODY$
LANGUAGE plpgsql;
This can only be done in a BEFORE trigger:
CREATE TRIGGER triggerinsert
BEFORE INSERT
ON rdpr
FOR EACH ROW
EXECUTE PROCEDURE function_update();
I Solved by writing trigger function like
CREATE OR REPLACE FUNCTION function_update()
RETURNS trigger AS
$BODY$
BEGIN
new.geom := ST_SetSRID(ST_MakePoint(new.longitude, new.latitude), 4326);
RETURN new;
END;
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;
ALTER FUNCTION function_update()
OWNER TO postgres;
and i wrote trigger to update
CREATE TRIGGER triggerinsert
Before INSERT
ON rdpr
FOR EACH ROW
EXECUTE PROCEDURE function_update();
I created a trigger when a row updated trigger will change that row. When I update a column I get an error. How can I solve?
ERROR: stack depth limit exceeded
HINT: Increase the configuration parameter "max_stack_depth" (currently 2048kB), after ensuring the platform's stack depth limit is adequate.
CREATE OR REPLACE FUNCTION ynt_call()
RETURNS TRIGGER AS $$
BEGIN
IF TG_OP = 'UPDATE' THEN
UPDATE ynt.a_test SET date_time = now();
END IF;
RETURN NEW;
END;
$$ language 'plpgsql';
CREATE TRIGGER update_call AFTER UPDATE ON ynt.a_test FOR EACH ROW EXECUTE PROCEDURE ynt_call();
Of course you're looping until the end of time, because you are updating row when updating row. You should set the field date_time using the special variable new as following:
CREATE OR REPLACE FUNCTION ynt_call()
RETURNS TRIGGER AS $$
BEGIN
IF TG_OP = 'UPDATE' THEN
new.date_time = now();
END IF;
RETURN NEW;
END;
$$ language 'plpgsql';
CREATE TRIGGER update_call AFTER UPDATE ON ynt.a_test FOR EACH ROW EXECUTE PROCEDURE ynt_call();