I am getting this error while declaring variables in this postgres query , really not sure what the issue is,I am new to postgres. thank for feedback
DECLARE
maxpagecount integer;
rowsofpage integer;
pagenumber integer;
Set rowsofpage :=3;
Set pagenumber :=1;
select maxpagecount=count(*) from UNLABELED_IMAGE_PREDICTION;
Set maxpagecount = CEILING(Maxpagecount/rowsofpage);
While maxpagecount >= pagenumber
BEGIN
Select x.image_id,x.score
from (
select *,row_number() over (order by score desc) as row_count
from UNLABELED_IMAGE_PREDICTION
) x
where x.row_count <= (select count(*) from UNLABELED_IMAGE_PREDICTION)
OFFSET (pagenumber-1)* rowsofpage ROWS
FETCH first rowsofpage ROWS ONLY;
Set rowsOfpage =rowsOfpage + 1
Set pagenumber=pagenumber+1
END;
Related
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;
$$
EDIT: I am creating a new question as per suggestion from sticky bit.
I have a query with CTEs to output results for several values (1 to 12). Below is a simplified example. Running it I got the following error:
ERROR: query has no destination for result data
HINT: If you want to discard the results of a SELECT, use PERFORM instead.
CONTEXT: PL/pgSQL function inline_code_block line 8 at SQL statement
I can't output the result of Select in a table. How can I solve this problem?
DO $$
DECLARE r integer;
BEGIN
r := 1;
WHILE r <= 2
LOOP
r := r + 1;
WITH params AS (
SELECT r AS rownumber
),
time AS (
SELECT id
FROM params, analysis
ORDER BY date DESC
LIMIT 1
OFFSET (SELECT rownumber - 1 from params)
)
SELECT * FROM time;
END LOOP;
END; $$;
An example of what I mentioned in my comment:
DO $$
DECLARE
r integer;
int_var integer;
BEGIN
r := 1;
WHILE r <= 12 LOOP
WITH params AS (
SELECT r AS rownumber
),
time AS (
SELECT id
FROM params, analysis
ORDER BY date DESC
LIMIT 1
OFFSET (SELECT rownumber - 1 from params)
)
SELECT INTO int_var id FROM time;
RAISE NOTICE 'id: %', int_var;
r := r + 1;
END LOOP;
END; $$;
You can't RETURN a value from a DO function, but you can RAISE NOTICE a value as above. The SELECT INTO will eliminate the error as you are giving the SELECT a destination(the int_var) for its output. NOTE: SELECT INTO inside plpgsql is different then the same command outside. Outside it is equivalent to CREATE TABLE AS.
DROP FUNCTION IF EXISTS top_5(customers.customerid%TYPE, products.prod_id%TYPE, orderlines.quantity%TYPE) CASCADE;
CREATE OR REPLACE FUNCTION top_5(c_id customers.customerid%TYPE, p_id products.prod_id%TYPE, quant orderlines.quantity%TYPE)
RETURNS orders.orderid%TYPE AS $$
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;
I am trying to do an update on a specific record every 1000 rows using Postgres. I am looking for a better way to do that. My function is described below:
CREATE OR REPLACE FUNCTION update_row()
RETURNS void AS
$BODY$
declare
myUID integer;
nRow integer;
maxUid integer;
BEGIN
nRow:=1000;
select max(uid_atm_inp) from tab into maxUid where field1 = '1240200';
loop
if (nRow > 1000 and nRow < maxUid) then
select uid from tab into myUID where field1 = '1240200' and uid >= nRow limit 1;
update tab
set field = 'xxx'
where field1 = '1240200' and uid = myUID;
nRow:=nRow+1000;
end if;
end loop;
END; $BODY$
LANGUAGE plpgsql VOLATILE
How can I improve this procedure? I think there is something wrong. The loop does not end and takes too much time.
To perform this task in SQL, you could use the row_number window function and update only those rows where the number is divisible by 1000.
Your loop doesn't finish because there is no EXIT or RETURN in it.
I doubt you could ever rival the performance of a standard SQL update with a procedural loop. Instead of doing it a row at a time, just do it all as a single statement:
with t2 as (
select
uid, row_number() over (order by 1) as rn
from tab
where field1 = '1240200'
)
update tab t1
set field = 'xxx'
from t2
where
t1.uid = t2.uid and
mod (t2.rn, 1000) = 0
Per my comment, I am presupposing what you mean by "every 1000th row," as without some designation of how to determine what tuple is what row number. That is easily edited by changing the "order by" criteria.
Adding a second where clause on the update (t1.field1 = '1240200') can't hurt but might not be necessary if these are nested loop.
This might be notionally similar to what Laurenz has in mind.
I solved this way:
declare
myUID integer;
nRow integer;
rowNum integer;
checkrow integer;
myString varchar(272);
cur_check_row cursor for select uid , row_number() over (order by 1) as rn, substr(fieldxx,1,244)
from table where field1 = '1240200' and uid >= 1000 ORDER BY uid;
BEGIN
open cur_check_row;
loop
fetch cur_check_row into myUID, rowNum, myString;
EXIT WHEN NOT FOUND;
select mod(rowNum, 1000) into checkrow;
if checkrow = 0 then
update table
set fieldxx= myString||'O'
where uid in (myUID);
end if;
end loop;
close cur_check_row;
I've created this function to re-sequence the sequence number on a BOM table (bomitem).
CREATE OR REPLACE FUNCTION seqincr(integer)
RETURNS SETOF bomitem AS
$BODY$
DECLARE
pItemid ALIAS FOR $1;
_row bomitem%ROWTYPE;
seqint int;
_id int;
BEGIN
seqint=8;
FOR _row IN SELECT *
FROM bomitem
WHERE ((bomitem_parent_item_id=pItemid))
LOOP
RETURN NEXT _row;
_id = _row.bomitem_id;
seqint = seqint+2;
update bomitem set bomitem_seqnumber = seqint where bomitem_id=_id;
END LOOP;
RETURN;
END;
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100
ROWS 1000;
ALTER FUNCTION seqincr(integer)
OWNER TO admin;
The example works on an individual bomitem_parent_item_id like below:
SELECT * from seqincr(14917);
I would like to rewrite this function to loop through
SELECT distinct bomitem_parent_item_id FROM bomitem;
so that it resequences the entire BOM table.
What you are trying to do is much simpler with a CTE:
WITH x AS (
SELECT bomitem_parent_item_id
, row_number() OVER (ORDER BY bomitem_parent_item_id) AS rn
FROM bomitem
GROUP BY bomitem_parent_item_id
ORDER BY bomitem_parent_item_id
)
UPDATE bomitem b
SET bomitem_seqnumber = 8 + 2 * rn
FROM x
WHERE x.bomitem_parent_item_id = b.bomitem_id;
You need at least PostgreSQL 9.1 for data-modifying CTE.
Or use a subquery, works in earlier versions, too:
UPDATE bomitem b
SET bomitem_seqnumber = 8 + 2 * rn
FROM (
SELECT bomitem_parent_item_id
, row_number() OVER (ORDER BY bomitem_parent_item_id) AS rn
FROM bomitem
GROUP BY bomitem_parent_item_id
ORDER BY bomitem_parent_item_id
) x
WHERE x.bomitem_parent_item_id = b.bomitem_id;
But you need at least PostgreSQL 8.4 for the window function row_number().