I have a trigger function in MySQL written as such:
CREATE TRIGGER after_customers_insert
BEFORE INSERT
ON customers FOR EACH ROW
BEGIN
SET #created := (SELECT IFNULL(created_at, NOW()) FROM customers ORDER BY created_at
DESC LIMIT 1);
IF YEAR(#created) <> YEAR(NEw.created_at) THEN
SET NEW.Newid := 1;
ELSE
SET NEW.Newid := (SELECT IFNULL(MAX(Newid),0) + 1 FROM customers);
END IF;
SET NEW.custom_id = CONCAT('KR_',DATE_FORMAT(now(), '%y'),'_',LPAD(NEW.Newid,3,'0'));
END
I tried to convert in Postgres this:
CREATE OR REPLACE FUNCTION after_customers_insert()
RETURNS trigger AS
$BODY$
BEGIN
SET #created := (SELECT IFNULL(created_at, NOW()) FROM customers ORDER BY created_at DESC LIMIT 1);
IF YEAR(#created) <> YEAR(NEw.created_at) THEN
SET NEW.Newid := 1;
ELSE
SET NEW.Newid := (SELECT IFNULL(MAX(Newid),0) + 1 FROM customers);
END IF;
SET NEW.custom_id = CONCAT('KR_',DATE_FORMAT(now(), '%y'),'_',LPAD(NEW.Newid,3,'0'));
END
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;
but without success. Any help please??
Related
I have a query which updates the records based on variables old_id and new_id. But condition is I need to fetch the variables dynamically. Here is simple query which I am using.
do
$$
declare
old_id bigint = 1561049391647687270;
declare new_id bigint = 2068236279446765699;
begin
update songs set poet_id = new_id where poet_id = old_id;
update poets set active = true where id = new_id;
update poets set deleted = true where id = old_id;
end
$$;
I need to assign the old_id and new_id dynamically
do
$$
declare
su record;
pc record;
old_id bigint;
new_id bigint;
begin
for pc in select name, count(name)
from poets
where deleted = false
group by name
having count(name) > 1
order by name
loop
for su in select * from poets where name ilike pc.name
loop
-- old_id could be null where I have 2 continue the flow without update
for old_id in (select id from su where su.link is null)
loop
raise notice 'old: %', old_id;
end loop;
-- new_id could be more than 2 skip this condition as well
for new_id in (select id from su where su.link is not null)
loop
raise notice 'new: %', new_id;
end loop;
end loop;
-- run the statement_1 example if new_id and old_id is not null
end loop;
end
$$;
The expected problem statement (to assign variable and use it in further execution) is with in comment.
(a) In your first "simple query", the update of the table poets could be automatically executed by a trigger function defined on the table songs :
CREATE OR REPLACE FUNCTION songs_update_id ()
RETURNS trigger LANGUAGE plpgsql AS
$$
BEGIN
UPDATE poets SET active = true WHERE id = NEW.poet_id ;
UPDATE poets SET deleted = true WHERE id = OLD.poet_id ; -- SET active = false to be added ?
END ;
$$ ;
CREATE OR REPLACE TRIGGER songs_update_id AFTER UPDATE OF id ON songs
FOR EACH ROW EXECUTE songs_update_id () ;
Your first query can then be reduced as :
do
$$
declare
old_id bigint = 1561049391647687270;
declare new_id bigint = 2068236279446765699;
begin
update songs set poet_id = new_id where poet_id = old_id;
end
$$;
(b) The tables update could be performed with a sql query instead of a plpgsql loop and with better performances :
do
$$
BEGIN
UPDATE songs
SET poet_id = list.new_id[1]
FROM
( SELECT b.name
, array_agg(b.id) FILTER (WHERE b.link IS NULL) AS old_id
, array_agg(b.id) FILTER (WHERE b.link IS NOT NULL) AS new_id
FROM
( SELECT name
FROM poets
WHERE deleted = false
GROUP BY name
HAVING COUNT(*) > 1
-- ORDER BY name -- this ORDER BY sounds like useless and resource-intensive
) AS a
INNER JOIN poets AS b
ON b.name ilike a.name
GROUP BY b.name
HAVING array_length(old_id, 1) = 1
AND array_length(new_id, 1) = 1
) AS list
WHERE poet_id = list.old_id[1] ;
END ;
$$;
This solution is not tested yet and could have to be adjusted in order to work correctly. Please provide the tables definition of songs and poets and a sample of data in dbfiddle so that I can test and adjust the proposed solution.
create or replace function trace.get_latest_exception_custom_msg(id varchar)
returns varchar
language plpgsql
as $$
declare
msg varchar ;
begin
perform t1.message, t1.created_time from table_1 t1 where t1.id = id order by t1.created_time desc limit 1;
perform t2.message, t2.created_time from table_2 t2 where t2.id = id order by t2.created_time desc limit 1;
if date(t1.created_time ) >= date(t2.created_time) then msg= t1.message;
elsif d date(t1.created_time ) < date(t2.created_time) then msg= t1.message;
else msg =t1.message;
end if;
return msg;
end;
while i call this function it give error ERROR: missing FROM-clause entry for table "t_1
You need to store the result of the two SELECT queries into variables in order to be able to be able to use them in an IF statement.
Your IF statement is also a bit confusing as all three parts assign the same value to msg. I assume that you want to use t2.message at least in one case.
create or replace function trace.get_latest_exception_custom_msg(p_id varchar)
returns varchar
language plpgsql
as
$$
declare
t1_msg varchar;
t1_created date;
t2_msg varchar;
t2_created date;
msg varchar;
begin
select t1.message, t1.created_time::date
into t1_msg, t1_created
from table_1 t1
where t1.id = p_id
order by t1.created_time desc
limit 1;
select t2.message, t2.created_time::date
into t2_msg, t2_created
from table_2 t2
where t2.id = p_id
order by t2.created_time desc
limit 1;
if t1_created >= t2_created then
msg := t1_msg;
elsif t1_created < t2_created then
msg := t2_msg; --<< ???
else
-- this can only happen if one (or both) of the DATEs is NULL.
msg := t1_msg;
end if;
return msg;
end;
$$
I have problem when create function for trigger. I want to UPDATE inserted value BEFORE INSERT data to DB.
My code look like this:
CREATE OR REPLACE FUNCTION test_func()
RETURNS TRIGGER AS
$$
DECLARE cnt INTEGER;
BEGIN
cnt := COUNT(*) FROM sample_tbl WHERE id = NEW.id AND created_date = NEW.created_date;
NEW.current_order := cnt + 1; // I want to set value of sample_tbl.current_order automatically
END
$$ LANGUAGE plpgsql;
CREATE TRIGGER test_trigger
BEFORE INSERT
ON test_tbl
FOR EACH ROW
EXECUTE PROCEDURE test_func();
I inserted data then IDE said:
control reached end of trigger procedure without RETURN
Where: PL/pgSQL function test_func()
The error says that you must return something from the Trigger ( either NEW or NULL )
There's no Trigger needed for this. A simple View using this select query will give you the required result
--create or replace view sample_view as
select t.id, t.created_date,
row_number() OVER ( partition by id,created_date order by id ) as current_order
FROM sample_tbl t;
This will exactly match the records if updated using a Trigger
CREATE OR REPLACE FUNCTION test_func()
RETURNS TRIGGER AS
$$
DECLARE cnt INTEGER;
BEGIN
select COUNT(*) INTO cnt FROM sample_tbl WHERE id = NEW.id
AND created_date = NEW.created_date;
NEW.current_order := cnt + 1;
RETURN NEW; --required
END
$$ LANGUAGE plpgsql;
Demo
Your trigger function is just missing RETURN NEW; statement:
CREATE OR REPLACE FUNCTION test_func()
RETURNS TRIGGER AS
$$
DECLARE cnt INTEGER;
BEGIN
cnt := COUNT(*) FROM sample_tbl WHERE id = NEW.id AND created_date = NEW.created_date;
NEW.current_order := cnt + 1;
RETURN NEW;
END
$$ LANGUAGE plpgsql;
DROP FUNCTION IF EXISTS top_5(customers.customerid%TYPE, products.prod_id%TYPE, orderlines.quantity%TYPE) CASCADE;
CREATE OR REPLACE FUNCTION top_5(c_id customers.customerid%TYPE, p_id products.prod_id%TYPE, quant orderlines.quantity%TYPE)
RETURNS orders.orderid%TYPE AS $$
DECLARE
top_prod CURSOR IS
SELECT inv.prod_id
FROM inventory AS inv, products AS prod
WHERE inv.prod_id=prod.prod_id
ORDER BY inv.quan_in_stock desc, inv.sales
limit 5;
ord_id orders.orderid%TYPE;
ord_date orders.orderdate%TYPE:= current_date;
ordln_id orderlines.orderlineid%TYPE:=1;
BEGIN
SELECT nova_orderid() INTO ord_id;
INSERT INTO orders(orderid, orderdate,customerid,netamount,tax,totalamount) VALUES(ord_id,ord_date,c_id,0,0,0);
PERFORM compra(c_id, p_id, 1::smallint, ord_id, ordln_id, ord_date);
IF (p_id = top_prod) THEN
UPDATE orders
SET totalamount = totalamount - (totalamount*0.2)
WHERE ord_id = (SELECT MAX(ord_id) FROM orders);
END IF;
END;
$$ LANGUAGE plpgsql;
I have the following code and when i try to execute this
SELECT top_5(1,1,'2');
i have this error
ERROR: operator does not exist: integer = refcursor
LINE 1: SELECT (p_id = top_prod)
You need to get the 'prod_id' value from the cursor 'top_prod'.
You cannot compare two types.
Try this,
DECLARE
top_prod_id top_prod%ROWTYPE;
BEGIN
OPEN top_prod;
LOOP
FETCH top_prod INTO top_prod_id;
EXIT WHEN top_prod %NOTFOUND;
IF (p_id = top_prod_id) THEN
UPDATE orders
SET totalamount = totalamount - (totalamount*0.2)
WHERE ord_id = (SELECT MAX(ord_id) FROM orders);
END IF;
END LOOP;
CLOSE top_prod;
END;
My Check constraint is as follows:
ALTER TABLE tablename
ADD CONSTRAINT check_duplicate_rows
CHECK (reject_duplicate_rows(columnB, columnC, columnD) < 2);
I want the constraint to be evaluated only when you insert a record.
Currently it does for both the insert and update statements, The problem is that my system needs to update the inserted rows and the check constraint blocks the updates.
The reject_duplicate_rows function is as follows:
CREATE OR REPLACE FUNCTION reject_duplicate_rows(columnB integer, columnC integer, columnD integer)
RETURNS integer AS
$BODY$
DECLARE
results INTEGER := 1;
v_count INTEGER := 0;
BEGIN
IF columnC <> 23 THEN
RETURN results;
END IF;
SELECT total INTO v_count FROM
(SELECT columnB,
columnC,
columnD,
count(*) AS total
FROM table_name
WHERE B = columnB AND C = columnC AND D = columnD
GROUP BY 1, 2, 3)
as temp_table;
IF COALESCE(v_count, 0) = 0 THEN
RETURN results;
END IF;
IF v_count >= 1 THEN
results := 2;
END IF;
RETURN results;
EXCEPTION
WHEN OTHERS THEN
RETURN results;
END;
$BODY$
LANGUAGE plpgsql VOLATILE
COST 1000;
ALTER FUNCTION reject_duplicate_rows(integer, integer, integer)
OWNER TO postgres
Have you tried to create an UPDATE trigger? see Creating postgresql trigger