i notice that this row inside the body of a trigger
V_SYSTIMESTAMP TIMESTAMP(6) DEFAULT SYSTIMESTAMP;
wrote in this place of the script, between the DECLARE and BEGIN keyword
DECLARE
V_SYSTIMESTAMP TIMESTAMP(6) DEFAULT SYSTIMESTAMP;
BEGIN
.....
END;
caused some problem for the indentation when i display the DDL script preview for the table.
Inside that script i see the trigger section write without indentation and new lines.
if i declare V_SYSTIMESTAMP otherwise like
V_SYSTIMESTAMP NUMBER;
i don't have the same problem during the preview.
The display of the DDL preview for only the trigger is right.
an example if i declare number var:
CREATE OR REPLACE TRIGGER ARC.TRG322 BEFORE
INSERT OR UPDATE ON ARC.TABLE
FOR EACH ROW
DECLARE
A NUMBER;
BEGIN
NULL;
END;
if i use timestamp i have this, boby write in one row
CREATE OR REPLACE TRIGGER ARC.Trg322
BEFORE INSERT OR UPDATE ON ARC.TABLE
FOR EACH ROW DECLARE
A TIMESTAMP;
BEGIN NULL ; END ;
thanks;
Related
I created a table name Student in PostgreSQL and then I tried defining a trigger on that table but it's showing an error message in doing so.
Trigger Syntax:
CREATE TRIGGER bi_Student BEFORE INSERT ON Student as $$
FOR EACH ROW
BEGIN
raise notice 'Successfully inserted into table(%)', user;
end $$;
Table Creation Command:
create table Student(Stu_id int, Stu_Name text, Stu_Age int, Stu_address char(30));
Actually I tried to declare the execution statements directly inside the trigger only rather than calling any procedure/ function from the trigger which is working fine but I want to do in this way in PostgreSQL.
PostgreSQL doesn't support it. You need trigger function always.
As documented in the manual you need a trigger function
create function my_trigger_function()
returns trigger
as
$$
begin
raise notice 'Successfully inserted into table(%)', user;
return new; --<< important (see the manual for details)
end
$$
language plpgsql;
Not sure what you intend with the user parameter there, as that is not the table name, but the current database user. If you want to display the actual table name, you need to use TG_RELNAME instead - which is an implicit variable available in the trigger function.
And a trigger definition
CREATE TRIGGER bi_Student
BEFORE INSERT ON Student
FOR EACH ROW
execute function my_trigger_function();
I have an already made table:
cotizacion(idCot(PK), unit_price,unit_price_taxes)
I need to convert unit_price_taxes into a generated column that is equal to unit_price*1.16. The issue is I can't find the alter table statement which will give me this. Dropping table and creating it again is not an option as this table is already deeply linked with the rest of the database and reinserting all records is not an option at this point.
I tried the following:
ALTER TABLE cotizacion
alter column unit_price_taxes set
GENERATED ALWAYS AS (unit_price*1.16) STORED;
But it's not working. Does anybody know how to get this done or if it's even possible? I would like to avoid creating a new column.
Thanks!
**EDIT:
I also tried the following trigger implementation:
CREATE OR REPLACE FUNCTION calculate_price_taxes()
RETURNS trigger
LANGUAGE plpgsql
AS $function$
declare pu money;
begin
select unit_price from cotizacion into pu
where idCot = new."idCot";
update cotizacion
set unit_price_taxes = pu * (1.16)
where idCot = new."idCot";
return new;
end;
$function$
;
And the trigger delcaration:
Create or replace trigger price_taxes
after update on cotizacion
for each row
execute procedure
calculate_price_taxes()
The most probable reason for your trigger to go into an infinite recursion is that you are running an UPDATE statement inside the trigger - which is the wrong thing to do. Create a before trigger and assign the calculated value to the new record:
create trigger update_tax()
returns trigger
as
$$
begin
new.unit_price_taxes := unit_price * 1.16;
return new;
end;
$$
language plpgsql;
create trigger update_tax_trigger()
before update or insert on cotizacion
for each row execute procedure update_tax();
The only way to "convert" that column to a generated one, is to drop it and add it again:
alter table cotizacion
drop unit_price_taxes;
alter table cotizacion
add unit_price_taxes numeric generated always as (unit_price*1.16) stored;
Note that this will rewrite the entire table which will block access to it. Adding the trigger will be less invasive.
I have a table with three columns: id, date and dateDekete
I try to execute an update on the column dateDelete after an update on another column (column date) using a AFTER UPDATE TRIGGER.
The code that I use to create my trigger is the following:
CREATE OR REPLACE FUNCTION update_delete_date_allocation()
RETURNS trigger LANGUAGE plpgsql AS $body$
BEGIN
NEW."dateDelete" := NEW.date + 1;
RETURN NEW;
END;
$body$;
CREATE TRIGGER delete_date_allocation_trg
AFTER INSERT OR UPDATE ON client.client_portfolio_allocation
FOR EACH ROW
EXECUTE PROCEDURE update_delete_date_allocation();
Although the code executes fine with no error message, the latter column that I try to update does not change.
I was wondering if it's possible to do this. AND if so, what should I change in my code?
I am using Postgres 11.5.
you can't change the new record in an AFTER trigger, you need to declare your trigger as a BEFORE trigger:
CREATE TRIGGER delete_date_allocation_trg
BEFORE INSERT OR UPDATE ON client.client_portfolio_allocation
FOR EACH ROW
EXECUTE PROCEDURE update_delete_date_allocation();
I have created an before update and after update trigger on a postgresql db table.
There is a requirement to preserve historical record and at the same time create a new record for the said data. Old record is to be marked as archived.
I was planning on using temporary table to keep track of the NEW values and reset the NEW values such that it is marked as archived.
In my after update trigger I would read the data from the temporary table, and create a brand new active record.
My problem is temporary table created in before update trigger is not visible to after update trigger. Moreover I cannot even pass on any argument (of type record) to the after update trigger as it is not allowed.
I have already achieved the desired result in Oracle db, using Global Temporary table, but having a tough time in PostgreSQL.
Here is the sample code for before update trigger function:
CREATE OR REPLACE FUNCTION trigger_fct_trig_trk_beforeupdate()
RETURNS trigger AS
$BODY$
DECLARE
some variable declarations;
BEGIN
Drop table IF EXISTS track_tmp_test;
CREATE TEMPORARY TABLE track_tmp_test(
...
);
Insert into track_tmp_test (........)
values(NEW., NEW..., NEW.., NEW...);
NEW... := OLD...;
NEW... := OLD.... ;
NEW... := OLD...;
Mark the NEW.status : = 'archived';
RETURN NEW;
END
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;
CREATE TRIGGER trig_trk_test_beforeupdate
BEFORE UPDATE ON test
FOR EACH ROW EXECUTE PROCEDURE trigger_fct_trig_trk_beforeupdate() ;
NOW the after UPDATE trigger function:
CREATE OR REPLACE FUNCTION trigger_fct_trg_trk_afterupdate()
RETURNS trigger AS
$BODY$
DECLARE
some variables;
-- insert into original table the data from temporary that was inserted in before update trigger
INSERT into TEST (....)
select ....
from track_tmp_test ;
-- delete data from temporary table after insert
delete from track_tmp_test ;
EXCEPTION
WHEN OTHERS THEN
-- Consider logging the error and then re-raise
RAISE;
RETURN NEW;
END
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;
Is there a way that after update trigger can access the temporary table created in before update trigger function?
I cannot have a permanent table hold he values, as trigger can be fired by many users updating the data in the table.
There is no problem with access to temporary table from triggers, and following code working without issue (on PostgreSQL 9.4):
CREATE OR REPLACE FUNCTION public.f1()
RETURNS trigger
LANGUAGE plpgsql
AS $function$
begin
drop table if exists bubu;
create temp table bubu(a int);
insert into bubu values(10);
return new;
end
$function$
CREATE OR REPLACE FUNCTION public.f2()
RETURNS trigger
LANGUAGE plpgsql
AS $function$
declare r record;
begin
for r in select * from bubu
loop
raise notice '%', r;
end loop;
return null;
end
$function$
create trigger xx
before insert on omega
for each row execute procedure f1();
create trigger yy
after insert on omega
for each row execute procedure f2();
postgres=# insert into omega values(333);
NOTICE: (10)
INSERT 0 1
So I am sure, so your problem will not be in access to temporary tables. It works well. There can be a issue on some 8.2, 8.3 and older with invalid plans due reference on dropped objects. Isn't it your problem?
I can say, so your design is wrong - there is not any reason, why you have to use a temp table. Same job you can do in after trigger. Any operations inside triggers should be fast, pretty fast. Dropping or creating temporary table is not fast operation.
If you have a older PostgreSQL release, you have not to drop temp table every. You should to delete content only. See a article http://postgres.cz/wiki/Automatic_execution_plan_caching_in_PL/pgSQL
The temporary table should be visible as #Pavel explains, but that's not the main issue here.
Your approach might make sense in Oracle with a global temporary table. But the posted Postgres code does not.
The trigger is fired for each row. You would (drop and) create a temp table for every row, and call another trigger, just to do what you could easily do in one trigger directly.
Instead, to keep the old row and set it to archived, plus INSERT a copy of the NEW row:
Demo table:
CREATE TEMP TABLE test (id int, txt text, archived bool DEFAULT FALSE);
Trigger func:
CREATE OR REPLACE FUNCTION trg_test_beforeupdate()
RETURNS trigger AS
$func$
BEGIN
INSERT INTO test SELECT (NEW).*; -- insert a copy of the NEW row
SELECT (OLD).* INTO NEW; -- revert row to previous state
NEW.archived = TRUE; -- just set it to "archived"
RETURN NEW;
END
$func$ LANGUAGE plpgsql;
Trigger:
CREATE TRIGGER beforeupdate
BEFORE UPDATE ON test
FOR EACH ROW EXECUTE PROCEDURE trg_test_beforeupdate();
Test:
INSERT INTO test VALUES (1, 'foo'), (2, 'bar');
UPDATE test SET txt = 'baz' WHERE id = 1;
SELECT * FROM test;
Works.
I have a table being created in a PostgreSQL ( version 9 ) database by a third party product and I need to change that table to add a new column then set the column in question to a standard value.
I have the following in my function:
CREATE FUNCTION alterscorecolumns()
RETURNS void AS
$BODY$
ALTER TABLE "hi_scores" ADD "total_score" integer;
UPDATE "hi_scores" SET total_score = score1+score2+score3;
$BODY$
However, I'm not allowed to do this because it doesn't know that the total_score field exists. I just get the message ERROR: column "total_score" of relation "hi_scores" does not exist.
I am guessing there is some execution-plan related reason for this and that maybe I need to tell it to run the ALTER TABLE before it tries to perform the update, but I can't seem to figure out what I need to do.
You can't do it that way. The SQL in the function is parsed when you create the function. At the time of the creation of the function the column is not there, so you get the error message.
You will need to use dynamic SQL to run the UPDATE statement.
Something like:
CREATE FUNCTION alterscorecolumns()
RETURNS void AS
$BODY$
begin
execute 'ALTER TABLE hi_scores ADD total_score integer';
execute 'UPDATE hi_scores SET total_score = score1+score2+score3';
$BODY$
language plpgsql;
(Not tested, so there might be syntax errors in there)
Just add DEFAULT to your statement like this:
ALTER TABLE "hi_scores" ADD "total_score" integer DEFAULT 0;
#mu already provided: if you want to save this procedure as a function, you have to use dynamic SQL with EXECUTE. But only for the UPDATE. The ALTER TABLE statement works just fine.
As this is obviously a one-time operation (can't add the same column twice), it hardly makes sense to persist a function for the purpose. You could use a DO statement instead:
DO
$BODY$
BEGIN
ALTER TABLE hi_scores ADD total_score integer;
EXECUTE 'UPDATE hi_scores SET total_score = score1+score2+score3';
END;
$BODY$;
But then again, keep it simple: just execute two SQL statements. As soon as the ALTER TABLE is done, the UPDATE will just work normally. Inside a transaction or not - doesn't matter, as long you execute them in order.
ALTER TABLE hi_scores ADD total_score integer;
UPDATE hi_scores SET total_score = score1+score2+score3;