Trying to use trigger to delete a row from a table when a column with the same value is delete from the original table
CREATE OR REPLACE FUNCTION testFunc()
RETURNS trigger AS
$func$
BEGIN
DELETE FROM emergencyinfo
USING massacts
WHERE emergencyinfo.actid = massacts.id;
RETURN NEW;
END
$func$ LANGUAGE plpgsql;
Trigger;
CREATE TRIGGER test_trigger3
AFTER DELETE ON massacts
FOR EACH ROW EXECUTE PROCEDURE testFunc();
This does not work, when i execute query 'delete from massacts where id=5', the row deletes from massacts but the row that holds actid=5 in emergencyinfo does not delete.
However, when i try this trigger by updating a row's id to 5 in massacts table, the row in emergencyinfo with actid=5 does delete.
CREATE TRIGGER test_trigger3
AFTER UPDATE ON massacts
FOR EACH ROW EXECUTE PROCEDURE testFunc();
I have tried to use BEFORE DELETE instead of AFTER, same issue persisted.
Related
Is there any variant to create a trigger before insert and if the value is a value that exists already in table, just update it. I know about 'ON DUBLICATE KEY' or a 'ON CONFLICT' in PostgreSQL but I need a trigger just because it's a task in my university.
I tried to create it, but I get just an error about duplicate keys.
CREATE or replace FUNCTION trigger_function()
RETURNS TRIGGER
LANGUAGE PLPGSQL
AS $$
BEGIN
IF new.name in (select name from "Test")
then
update "Test" set intt = new.intt where name = new.name;
end if ;
return new;
END;
$$
CREATE TRIGGER trigger_name
BEFORE insert
ON "Test"
for each row
EXECUTE PROCEDURE trigger_function();
Is it possible to create such trigger?
Read the docs plpgsql trigger function:
Row-level triggers fired BEFORE can return null to signal the trigger manager to skip the rest of the operation for this row (i.e., subsequent triggers are not fired, and the INSERT/UPDATE/DELETE does not occur for this row).
So RETURN NULL after the UPDATE statement inside the if andRETURN NEW when the if is false. Then the INSERT will happen if the name is unique.
I have the requirement to move data from one table to another table when the value of one of the columns is updated. And I just want to move the updated row to the new table.
Below is my trigger that I have written. The issue with my code is, that it is moving all the data and not just the row which was updated. Can anyone give a suggestion?
create or replace function moveToAC1ControlHist()
returns trigger as $$
begin if NEW.file_status='CO'
then
insert into ac1_control_hist (file_status,identitifier)
(
select file_status,identitifier
from
ac1_control where new.FILE_STATUS = 'CO'
);
end if;
return new;
end;
$$ language plpgsql;
create TRIGGER AC1_CONTROL_TRIGGER AFTER update of file_status ON AC1_CONTROL
FOR EACH ROW when (new.file_status ='CO')EXECUTE PROCEDURE moveToAC1ControlHist();
I think the logic you want is:
create or replace function moveToAC1ControlHist()
returns trigger as
$$
begin
insert into ac1_control_hist (file_status,identitifier)
values (new.file_status, new.identitifier);
return null;
end;
$$ language plpgsql;
create trigger ac1_control_trigger
after update of file_status on ac1_control
for each row
when (new.file_status ='co')
execute function movetoac1controlhist()
;
Rationale:
you just want to copy (part of) the row being updated, so there is no need to select; you can access the values of the current row with new in a row-level trigger
the trigger definition filters on new file_status that is equal to 'CO', so there is no need for a if construct in the function
this is an after trigger, so you can just return null - the result is discarded anyway
I need some help.
I'm trying to create a Trigger that execute a procedure whenever insert, delete or update operations are done on a specific table.
This is the trigger
CREATE OR REPLACE NONEDITIONABLE TRIGGER NQDI.GAV_TRG
AFTER INSERT or UPDATE or DELETE ON D_GAV
FOR EACH ROW
BEGIN
PRC_FILL_D_GAV(:old.report_name);
END;
Unofortunately, since the trigger starts before any commit has been done and I need to read from the same table, it gives me the 'D_GAV table is being modified can't be read' error.
Besides, the FOR EACH ROW makes the trigger start for every record changed, while I want the trigger to start only at the end, when every update, insert or delete has been committed, but I haven't find a way to preserve the :old.report_name while doing this.
I know I could do what I want with an "up and running process", but I'd like to avoid that. Is there any other solution that I'm overlooking?
You want a compound trigger. After each row event you insert the data into an array. And after the statement you loop through the data and call your procedure.
create or replace trigger nqdi.gav_trg
for insert or update or delete on d_gav compound trigger
type type_table_of_gav is table of d_gav%rowtype;
v_gavs type_table_of_gav := type_table_of_gav();
after each row is
begin
v_gavs.extend(1);
v_gavs(v_gavs.count).report_name := coalesce(:old.report_name, :new.report_name);
end after each row;
after statement is
begin
for i in 1 .. v_gavs.count loop
prc_fill_d_gav(v_gavs(i).report_name);
end loop;
end after statement;
end gav_trg;
I've created a trigger as follows:
create or replace trigger "PASSENGERS_BACKUP_T1"
after
insert or update or delete on "PASSENGERS"
for each row
begin
if :NEW."P_ID" is NOT null then
INSERT INTO PASSENGERS_BACKUP(
PB_ID,
PB_FIRST_NAME,
PB_LAST_NAME,
PB_STREET_ADDRESS1,
PB_STREET_ADDRESS2,
PB_CITY,
PB_STATE,
PB_POSTAL_CODE,
PB_EMAIL,
PB_PHONE_NUMBER1,
PB_PHONE_NUMBER2,
PB_URL,
PB_CREDIT_LIMIT,
PB_TAGS)
VALUES (
:new.P_ID,
:new.P_FIRST_NAME,
:new.P_LAST_NAME,
:new.P_STREET_ADDRESS1,
:new.P_STREET_ADDRESS2,
:new.P_CITY,
:new.P_STATE,
:new.P_POSTAL_CODE,
:new.P_EMAIL,
:new.PHONE_NUMBER1,
:new.PHONE_NUMBER1,
:new.URL,
:new.CREDIT_LIMIT,
:new.TAGS);
end if;
end;
now, when I update​ an existing row in "passengers" table as per the above trigger another new row is getting added in "passengers_backup" table instead I would like to update the existing row whenever an update is done in "passengers" table rows. As, well If I delete a row in "Passengers" table, if that row exists in 'Passengers_backup' table it should also get deleted. How can I acheive this?
Thanks in advance.
For solving your problem you need to use trigger with corresponding SQL statement for each action: insert, update, delete. As variant you can use something like this (Note, I left only two columns from your example for readability, so modify your trigger as you need):
create or replace trigger "PASSENGERS_BACKUP_TIUD"
after insert or update or delete on "PASSENGER"
for each row
begin
if inserting then
insert into "PASSENGER_BACKUP" (pb_id, pb_first_name)
values (:NEW.pb_id, :NEW.pb_first_name);
elsif updating then
update "PASSENGER_BACKUP"
set pb_id=:NEW.pb_id, pb_first_name=:NEW.pb_first_name
where pb_id=:NEW.pb_id;
elsif deleting then
delete from "PASSENGER_BACKUP"
where pb_id=:OLD.pb_id;
end if;
end;
Also you can see work of this trigger in action on SQL Fiddle.
I would like to disable the DELETE statement on a table.
What I need to do is a SET a field value instead of removing the respective record.
So far I have tried the following:
CREATE TRIGGER delete_trg
INSTEAD OF DELETE
ON schema.tbl
FOR EACH ROW
EXECUTE PROCEDURE schema.tbl_delete_fn();
My schema.tbl_delete_fn() function is as follows:
CREATE OR REPLACE FUNCTION schema.tbl_delete_fn()
RETURNS trigger AS
BEGIN
NEW.deleted := true;
RETURN NEW;
END;
So far this doesn't seem to work... any ideas?
You want a BEFORE DELETE trigger whose function returns NULL and the row variable is OLD, not NEW.
CREATE TRIGGER delete_trg
BEFORE DELETE
ON schema.tbl
FOR EACH ROW
EXECUTE PROCEDURE schema.tbl_delete_fn();
CREATE OR REPLACE FUNCTION schema.tbl_delete_fn()
RETURNS trigger AS '
BEGIN
UPDATE schema.tbl SET deleted=true WHERE ctid=OLD.ctid;
RETURN NULL;
END; ' language plpgsql;
Or...
CREATE RULE delete_rule
AS ON DELETE TO schema.tbl
DO INSTEAD NOTHING;
Pros: Clearer, no code is called for each row visited, and no SP required.
Cons: Less standard than the trigger solution.