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;
Related
Hi I am trying to work out how to return a subset of a new row as json to a pg_notify function.
I am currently using
create or replace function public.notify_site()
returns trigger
language plpgsql
as $function$
begin
perform pg_notify('ppsite', row_to_json(NEW)::text);
RETURN new;
END;
$function$;
which works fine returning the entire row of data when the after insert trigger for the table fines, however, what I'm trying to do is return just a subset of NEW rather than the entire thing. It would be really cool if I could return the result of a select on NEW or something similar. Is this possible or does my receiving application need to sort the data out instead?
To be clear, I want to return json with say
NEW.c1, NEW.c2, NEW.c5 rather than the entire row of about 50 values.
Ta.
You can define the projection you want from the NEW record:
CREATE OR REPLACE FUNCTION public.notify_site()
RETURNS trigger
LANGUAGE plpgsql
AS $function$
declare
my_record record;
begin
select NEW.id as id, NEW.some_data as some_data INTO my_record;
perform pg_notify('pp_site', row_to_json(my_record)::text);
return NEW;
end;
$function$
;
I have a really simple problem and I am probably overthinking this way too much. But here it goes:
I want the fields of a column in one of my tables to be filled automatically whenever I make a new record. The value should be the same (UUID) as the specified (UUID) value from a column in another table. These two columns are joined via a foreign key. So far I have tried making a trigger function but with no results so far:
Create or replace function project_id()
returns trigger
as $$ begin
if new.project_id is null then
insert into sporen (project_id)
select project_id
from project_info
where project_code = 'ant0001';
end if;
return new;
end;
$$ language plpgsql;
CREATE TRIGGER
project_id_default
BEFORE update ON
sporen
FOR EACH ROW EXECUTE PROCEDURE project_id();
Do I need to specify something as a default in my table? Or am I going about it completely wrong?
You only need to assign project_info.project_id to NEW.project_id in your trigger function. No INSERT is needed. Here is an illustration.
Create or replace function project_id() returns trigger as
$$
begin
if new.project_id is null then
new.project_id :=
(
select pi.project_id
from project_info pi
where pi.project_code = NEW.project_code
);
end if;
return new;
end;
$$ language plpgsql;
You do not need to specify a default value for project_id in your table.
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 a test table with three columns (file, qty, qty_total). I will input multiple rows like this for example, insert into test_table (file,qty) VALUS (A,5);. What i want is for on commit is for a trigger to take the value from qty and add it to qty_total. As what will happen is that this value will get updated as this example demonstrates. Update test_table set qty = 10 where file = A; So the qty_total is now 15. Thanks
Managed to solve this myself. I created a trigger function `CREATE FUNCTION public.qty_total()
RETURNS trigger
LANGUAGE 'plpgsql'
COST 100.0
VOLATILE NOT LEAKPROOF
AS $BODY$
BEGIN
IF TG_OP = 'UPDATE' THEN
NEW."total" := (OLD.total + NEW.col2);
RETURN NEW;
ELSE
NEW."total" := NEW.col2;
RETURN NEW;
END IF;
END;
$BODY$;
ALTER FUNCTION public.qty_total()
OWNER TO postgres; This was called by a trigger CREATE TRIGGER qty_trigger
BEFORE INSERT OR UPDATE
ON public.test
FOR EACH ROW
EXECUTE PROCEDURE qty_total(); now when i insert a new code and value, the value is copied to the total, when it is updated, the value is added to the total and i have my new qty_total. This may not have the best error catching in it, but since i am passing the data from php, i am happy to make sure the errors are caught and removed.
I need help in Postgres triggers.
I have table with 2 columns:
sold boolean;
id_shop int;
It stores if item is sold, or at which shop its located at.
I need a trigger, if I change the "sold" to true, then it also changes the id_shop to NULL (It can't be in shop if sold...)
I tried different ways, but it doesn't work or gives an error on update cmd...
create or replace function pardota_masina_veikals() RETURNS trigger AS $pardota_masina$
begin
IF NEW.sold=true THEN
update masinas
SET id_shop=null WHERE id=NEW.id;
END IF;
RETURN NEW;
END;
$pardota_masina$ LANGUAGE plpgsql;
CREATE TRIGGER pardota_masina_nevar_but_veikala
AFTER INSERT OR UPDATE ON masinas FOR EACH ROW EXECUTE PROCEDURE pardota_masina_veikals();
First of all you need a before trigger if you want to change a value of the row being updated (or inserted)
Secondly you don't need to "update" the table, just assign the new value to the NEW row:
create or replace function pardota_masina_veikals()
RETURNS trigger
AS
$pardota_masina$
begin
IF NEW.sold=true THEN
NEW.id_shop = NULL;
END IF;
RETURN NEW;
END;
$pardota_masina$
LANGUAGE plpgsql;
CREATE TRIGGER pardota_masina_nevar_but_veikala
BEFORE INSERT OR UPDATE ON masinas
FOR EACH ROW EXECUTE PROCEDURE pardota_masina_veikals();