I have setup a trigger on my table to update inserted rows using a dblink. I used dblink because want the trigger to update the row async.
I have tested the dblink update in pgAdmin SQL query tool succesfully. However, when I insert a row the trigger runs but no rows are updated.
Is there something I'm missing regarding dblink?
CREATE OR REPLACE FUNCTION locates_data.async_update_geom()
RETURNS trigger AS
$BODY$
BEGIN
-- as this is an after trigger, NEW contains all the information we need even for INSERT
perform dblink('dbname=devtable00 host=10.1.1.98 port=5432 user=admin password=*****', 'update locates_data.request set geom = ST_Transform(ST_setSRID(ST_MakePoint('||NEW.longitude||','||NEW.latitude||'), 4326),3857) where request_pk = '||NEW.request_pk||'');
RAISE NOTICE 'UPDATING geo data for %, [%,%]' , NEW.request_pk, NEW.latitude, NEW.longitude;
RETURN NEW; -- result is ignored since this is an AFTER trigger
END;
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;
ALTER FUNCTION locates_data.async_update_geom()
Related
I am trying to create a trigger and procedure to update a last_changed_timestamp column upon UPDATE and INSERT.
I can register the function and trigger just fine, but when I try to update a record I receive the error.
CREATE OR REPLACE FUNCTION update_my_table_last_changed_timestamp()
RETURNS trigger AS
$BODY$
BEGIN
UPDATE my_table SET NEW.last_changed_timestamp = NOW();
RETURN NEW;
END;
$BODY$
LANGUAGE plpgsql;
CREATE TRIGGER trigger_update_my_table_last_changed_timestamp
BEFORE UPDATE
ON my_table
FOR EACH ROW
EXECUTE PROCEDURE update_my_table_last_changed_timestamp();
column "new" of relation "my_table" does not exist
I also do not fully understand how update_my_table_last_changed_timestamp knows which row it's suppose to update, nor if there were parameters passed to it, how the I would get those variables from the trigger to the procedure.
Modify the NEW record, there is no need to update.
BEGIN
NEW.last_changed_timestamp = NOW();
RETURN NEW;
END;
Read in the documentation: Overview of Trigger Behavior
If you still want to access a (other )table in the update trigger.
You can add to beginning of your trigger body the following:
EXECUTE format('SET search_path TO %I', TG_TABLE_SCHEMA);
For some reason with the update trigger it can happen that you're not on the correct search_path (i believe some old psql version have this)
I have 2 tables created :- Table Banks and Branch. Both the tables have column last_updated(which means when was the record last updated.) I have created after update trigger for each row on both the tables. The trigger and trigger function looks like below :-
create trigger banks_upd_trg
after update of phone_no
on Banks
FOR EACH ROW
EXECUTE PROCEDURE bankdetails_upd();
create trigger branch_upd_trg
after update of email_address
on Branch
FOR EACH ROW
EXECUTE PROCEDURE bankdetails_upd();
create or replace FUNCTION bankdetails_upd()
RETURNS trigger AS
$BODY$
BEGIN
EXECUTE format('update %I.%I SET last_updated=current_timestamp where id=new.id',TG_SHEMA_NAME,TG_TABLE_NAME)
RETURN NEW;
END;
$BODY$
LANGUAGE plpgsql
The trigger is getting executed successfully but isn't working at the time of updating phone_no and email_address column in Banks and Branch table respectively.
No need for dynamic SQL or an UPDATE statement.
Use a before trigger and assign the value to the NEW record.
create or replace FUNCTION bankdetails_upd()
RETURNS trigger AS
$BODY$
BEGIN
new.last_updated := current_timestamp;
RETURN NEW;
END;
$BODY$
LANGUAGE plpgsql;
create trigger banks_upd_trg
BEFORE update of phone_no
on Banks
FOR EACH ROW
EXECUTE PROCEDURE bankdetails_upd();
create trigger branch_upd_trg
BEFORE update of email_address
on Branch
FOR EACH ROW
EXECUTE PROCEDURE bankdetails_upd();
I'm trying to call a function from a trigger function and don't understand what control structure to use. Here's the situation:
I have 3 tables (table1, table2, table3) and two functions (Fct1 and Fct2).
Fct1 is a trigger function triggered after an insert in table1 and which makes insert in table2:
CREATE OR REPLACE FUNCTION Fct1()
RETURNS TRIGGER AS
$BODY$
BEGIN
TRUNCATE "table2";
INSERT INTO "table2"
SELECT ... FROM "table1";
RETURN NEW;
END;
$BODY$
LANGUAGE plpgsql VOLATILE
The trigger is:
CREATE TRIGGER trig_fct1
AFTER INSERT
ON table1
FOR EACH ROW
WHEN ((pg_trigger_depth() < 1))
EXECUTE PROCEDURE Fct1();
If I do after that a SELECT "Fct2"(); everything works fine, but if I add in Fct1 a PERFORM "Fct2"(); , like this:
CREATE OR REPLACE FUNCTION Fct1()
RETURNS TRIGGER AS
$BODY$
BEGIN
TRUNCATE "table2";
INSERT INTO "table2"
SELECT ... FROM "table1";
TRUNCATE "table3";
PERFORM "Fct2"(); -- will insert into table3
RETURN NEW;
END;
$BODY$
LANGUAGE plpgsql VOLATILE
It takes much more time to run (I never waited for the end, it's too long).
Fct2 looks like this
CREATE OR REPLACE FUNCTION "Fct2"()
RETURNS void AS
$BODY$
BEGIN
INSERT INTO "table3" ...;
RETURN;
END;
$BODY$
LANGUAGE plpgsql VOLATILE
So, there is something I don't understand and I think it is related to these 'RETURNs' which are not clear to me. I have tried different 'solutions' but I always got errors mentioning some 'return' mismatches. Any suggestions ?
I'm using PostgreSQL 9.6
To capture long running SQL statements from functions in the log, you can use auto_explain with auto_explain.log_nested_statements set to on. But if the query doesn't even finish, that won't help a lot.
My bet is that you are blocked by a database lock. Set log_lock_waits to on and see if something is reported in the log. You should also query pg_locks to see if there are locks requested but not granted.
I have a table (entry_table) filled with various geographic location data currently used by clients for our front end Web feature service. If a user deleted their entry in the WFS it is deleted in our postgres database. I would like to create a trigger that will run an INSERT command to copy the row(roughly 25 columns of data) to a second table(historical_entry_table) so if the entries are needed again in the future they can be easily retrieved.
Here's what I have working so far. I'm new to Triggers so I know the syntax is off. Not sure where to go from here. Im running postgres 8.4
In the table :
CREATE TRIGGER trigger_name BEFORE DELETE
ON entry_table
FOR EACH ROW
EXECUTE PROCEDURE trigger_backup_row
The Function itself:
CREATE OR REPLACE FUNCTION trigger_backup_row()
LANGUAGE SQL
RETURNS trigger AS
$BODY$
BEGIN
INSERT INTO historical_entry_table (col1, col2, etc) values (OLD.col1, OLD.col2, OL
RETURN NULL:
END;
$BODY$
I will put a working example here:
CREATE OR REPLACE FUNCTION trigger_backup_row()
RETURNS trigger AS
$BODY$
BEGIN
INSERT INTO PCIcards_backup (MODEL, SUBSYSTEM_DEVICE, ADAPTER, MAPPING) values (NEW.MODEL, NEW.SUBSYSTEM_DEVICE, NEW.ADAPTER, NEW.MAPPING);
RETURN NEW;
END;
$BODY$
language PLPGSQL
As you can see, you only need to set the language at the end of a file with param PLPGSQL because SQL cannot return triggers.
you have just about got it. your code here, updated :
CREATE OR REPLACE FUNCTION trigger_backup_row()
RETURN trigger AS
$BODY$
BEGIN
INSERT INTO historical_entry_table (col1, col2, etc) values (OLD.col1, OLD.col2, OLD.etc);
END;
$BODY$
Posting the correct version of the last answer:
CREATE OR REPLACE FUNCTION trigger_backup_row()
RETURN trigger
LANGUAGE plpgsql
AS
$$
BEGIN
INSERT INTO historical_entry_table (col1, col2, etc) values (OLD.col1, OLD.col2, OLD.etc);
RETURN new;
END;
$$
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.