I'm trying to set an "after insert" trigger that executes a procedure. The procedure would take all inserted rows in table A, group them by a column and insert the result in a table B. I know about "new" variable but it gets inserted rows one by one. Is it possible to get all of them?
I think I can't use a for each row statement as I need to group rows depending on the "trackCode" variable, shared by different rows in tableA.
CREATE OR REPLACE PROCEDURE Public.my_procedure(**inserted rows in tableA?**)
LANGUAGE 'plpgsql'
AS $$
BEGIN
INSERT INTO Public."tableB" ("TrackCode", "count")
SELECT "TrackCode", count(*) as "count" FROM Public."tableA" --new inserted rows in this table
GROUP BY "vmsint"."TrackCode" ;
COMMIT;
END;
$$;
create trigger Public.my_trigger
after insert ON Public.tableA
execute procedure Public.my_procedure(**inserted rows in tableA?**)
Thank you!
You create a statement lever trigger, but do not attempt to pass parameters. Instead use the clause referencing new table as reference_table_name. In the trigger function you use the reference_table_name in place of the actual table name. Something like: (see demo)
create or replace function group_a_ais()
returns trigger
language 'plpgsql'
as $$
begin
insert into table_b(track_code, items)
select track_code, count(*)
from rows_inserted_to_a
group by track_code ;
return null;
end;
$$;
create trigger table_a_ais
after insert on table_a
referencing new table as rows_inserted_to_a
for each statement
execute function group_a_ais();
Do not attempt to commit in a trigger, it is a very bad id even if allowed. Suppose the insert to the main table is part of a larger transaction, which fails later in its process.
Be sure to refer to links provided by Adrian.
Related
I have subscription data that is being appended to a table in real-time (via kafka). i have set up a trigger such that once the data is added it is checked for consistency. If checks pass some of the data should be added to other tables (that have master information on the customer profile etc.). The checks function i wrote works fine but i keep getting errors on the function used in the trigger. The function for the trigger is:
CREATE OR REPLACE FUNCTION update_tables()
RETURNS TRIGGER
LANGUAGE plpgsql
AS
$$
BEGIN
CASE (SELECT check_incoming_data()) WHEN 0
THEN INSERT INTO
sub_master(sub_id, sub_date, customer_id, product_id)
VALUES(
(SELECT sub_id::int FROM sub_realtime WHERE CTID = (SELECT MAX(CTID) FROM sub_realtime)),
(SELECT sub_date::date FROM sub_realtime WHERE CTID = (SELECT MAX(CTID) FROM sub_realtime)),
(SELECT customer_id::int FROM sub_realtime WHERE CTID = (SELECT MAX(CTID) FROM sub_realtime)),
(SELECT product_id::int FROM sub_realtime WHERE CTID = (SELECT MAX(CTID) FROM sub_realtime))
);
RETURN sub_master;
END CASE;
RETURN sub_master;
END;
$$
The trigger is then:
CREATE TRIGGER incoming_data
AFTER INSERT
ON claims_realtime_3
FOR EACH ROW
EXECUTE PROCEDURE update_tables();
What I am saying is 'if checks pass then select data from the last added row and add them to the master table'. What is the best way to structure this query?
Thanks a lot!
The trigger functions are executed for each row and you must use a record type variable called "NEW" which is automatically created by the database in the trigger functions. "NEW" gets only inserted records. For example, I want to insert data to users_log table when inserting records to users table.
CREATE OR REPLACE FUNCTION users_insert()
RETURNS trigger
LANGUAGE plpgsql
AS $function$
begin
insert into users_log
(
username,
first_name,
last_name
)
select
new.username,
new.first_name,
new.last_name;
return new;
END;
$function$;
create trigger store_data_to_history_insert
before insert
on users for each row execute function users_insert();
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 have a customer table.
I have created stored procedure I can use to insert new data into the table. But what if I wanted to use the same procedure to update OR delete data from that table. Could I do this easily or do I have to use a separate function/procedure for each function?
create or replace procedure add_customer(custid in table.id%type,
name table.name%type)
is
begin
insert into table(id, name)
values(id, name);
commit;
end;
/
You can add parameter like action in example below and use it in code:
create or replace procedure modify_customer(
action in varchar2, custid in table.id%type, custname table.name%type)
is
begin
if action = 'insert' then
insert into table(id, name) values(custid, name);
commit;
elsif action = 'delete' then
delete from table where id = custid and name = custname;
commit;
end if;
end;
You can add a discriminator parameter to your add_customer procedure which says whether the action is INSERT, UPDATE or DELETE. Based on this parameter you can create the required insert, update or delete statement. This way you will be able to use a common procedure for all the actions.
As far as using one procedure or multiple procedures, if the table is a simple one with limited number of columns, one procedure should do fine. But once the number of columns increases in the table, one procedure might become more complicated than required.
I want only to maintain present 1 month records log details. need to delete past record log details.I tried this code however could not work this,
create sequence userseq1;
CREATE TABLE users
( id integer NOT NULL DEFAULT nextval('userseq1'::regclass)
);
INSERT INTO users VALUES(126);
CREATE TABLE History
( userid integer
, createdate timestamp
);
CREATE OR REPLACE FUNCTION recordcreatetime() RETURNS trigger language plpgsql
AS $$
DECLARE
BEGIN
INSERT INTO History values(new.id,NOW() );
RETURN NEW;
END;
$$;
CREATE TRIGGER user_hist
BEFORE INSERT ON users
FOR EACH ROW
EXECUTE procedure recordcreatetime();
However it is working to insert values sequencing one by one adding.I want to delete the previous 1 month record Log details.I tried this below code and it is not working
CREATE OR REPLACE FUNCTION trf_keep_row_number_steady()
RETURNS TRIGGER AS
$body$
DECLARE
BEGIN
IF (SELECT count(createdate) FROM history) > rownum_limit
THEN
DELETE FROM history
WHERE createdate = (SELECT min(createdate) FROM history);
END IF;
END;
$body$
LANGUAGE plpgsql;
CREATE TRIGGER tr_keep_row_number_steady
AFTER INSERT ON history
FOR EACH ROW EXECUTE PROCEDURE trf_keep_row_number_steady();
I can see in your second code block, you have a trigger on history table and you are trying to DELETE FROM history in that same trigger.
Insert / Update / Delete on a table through a trigger on the same table is not allowed. Please think of some other alternative, e.g., running a separate DELETE statement for the required cleanup of rows before or after your main INSERT statement.
I need a query to move a record from one table to another without using multiple statements?
No, you cannot move records in one SQL statement. You have to use an INSERT followed by a DELETE statement. You should wrap these statements into a transaction, to make sure that the copy operation remains atomic.
START TRANSACTION;
INSERT INTO
new_table
SELECT
*
FROM
old_table
WHERE
some_field = 'your_criteria';
DELETE FROM old_table WHERE some_field = 'your_criteria';
COMMIT;
If you really want to do this in a single SQL statement, one way to accomplish this would be to create an "after delete" trigger on the source table that inserts the row into the target table. This way you can move the row from the source table to the target table simply by deleting it from the source table. Of course this will only work if you want to insert into target table for every delete on the source table.
DELIMITER $$
DROP TRIGGER IF EXISTS TR_A_DEL_SOURCE_TABLE $$
CREATE TRIGGER TR_A_DEL_SOURCE_TABLE AFTER DELETE ON SOURCE_TABLE FOR EACH ROW BEGIN
INSERT IGNORE INTO TARGET_TABLE(id,val1,val2) VALUES(old.id,old.va1,old.val2);
END $$
DELIMITER ;
So to move the row with id 42 from source table to target table:
delete from source_table where id = 42;
No - you might be able to do the INSERT in one nested statement, but you still need to remove the record.
There is no way to make it a single query, but if you HAVE to do it in a single query within an application you can create a Stored Procedure to do it for you.
DELIMITER $$
DROP PROCEDURE IF EXISTS `copydelete` $$
CREATE PROCEDURE `copydelete` (id INT)
BEGIN
INSERT INTO New_Table SELECT * from Old_Table WHERE Old_Table.IdField=id;
DELETE FROM Old_Table where IdField=id;
END $$
DELIMITER ;
Then you're new query is just
CALL copydelete(4);
Which will delete WHERE IdField=4;
Please note that the time delay between insert-select and delete can cause you to delete to much.
For a safe route you could use an update field:
update old_table set move_flag=1 where your_criteria
insert into ... select from ... where move_flag = 1
delete from old_table where move_flag=1
Or use a transaction which locks the old_table so no data can be added between insert... select and delete.