chaps and chapettes
Just a quick question. I need to return only one row from a stored proc., but no matter where I place the WHERE clause, I get errors. Can somebody take a look at the (cut-down due to sheer length) code and let me know where it should go, please?
SELECT **values**
INTO **variables**
FROM **table**
_WHERE ROWNUM = 1_
INNER JOIN **other table**
ON **join target**
ORDER BY **sort criteria**;
_WHERE ROWNUM = 1_
Thanks
I believe this is the way to structure rownum queries
SELECT * FROM
INTO **Variables * *
( SELECT * FROM X
WHERE Y
ORDER BY Z
)
WHERE ROWNUM = 1;
You were almost correct. You put the WHERE clause after the JOINs, but before the ORDER BY.
SELECT **values**
INTO **variables**
FROM **table**
INNER JOIN **other table**
ON **join target**
_WHERE ROWNUM = 1_
ORDER BY **sort criteria**;
However, this won't do what you might think - the ORDER BY is evaluated AFTER the where clause; which means this will just pick the first record it finds (that satisfies the join criteria), and will then sort that row (which obviously is a no-op).
The other answers (e.g. IvoTops') give ideas of how to get the first record according to the sort criteria.
SELECT **values**
INTO **variables**
FROM
( SELECT **values**
, ROW_MUMBER() OVER (ORDER BY **sort criteria**) AS rn
FROM **table**
INNER JOIN **other table**
ON **join target**
) tmp
WHERE rn = 1 ;
Check also this blog post: Oracle: ROW_NUMBER() vs ROWNUM
little bit late, but I got a similar problem and I solved it like this:
SELECT **values**
INTO **variables**
FROM **table**
WHERE **condition**
ORDER BY **sort criteria**
FETCH FIRST 1 ROW ONLY;
Regards
Related
We have a query run by our development team that's heavy in resources and looking at the explain plan, it looks like its uses the same data set multiple times. Is there anyway we can re-write this query.
Now, i tried to replace the co-related query with direct join but still the multiple co-related queries look the same apart from one minor difference.
select tb2.mktg_id, mktg_cd , count(distinct tb2.conf_id)
from
(select conf_id, count(distinct c.mktg_id) as num_cpg
from acc_latst c, off_latst ot
where c.mktg_id = ot.mktg_id and c.bus_eff_dt > '2019-01-01' and to_date(strt_tms) = '2019-01-10'
group by conf_id
having count(distinct c.mktg_id) >1
)tb1,
(select distinct conf_id, c.mktg_id, mktg_cd
from acc_latst c, off_latst ot
where c.mktg_id = ot.mktg_id and c.bus_eff_dt > '2019-01-01' and to_date(strt_tms) = '2019-01-10'
)tb2
where tb1.conf_id = tb2.conf_id group by tb2.mktg_id, mktg_cd
One way is using CTE -
with res1 as
(
select distinct conf_id, c.mktg_id, mktg_cd
from acc_latst c, off_latst ot
where c.mktg_id = ot.mktg_id and c.bus_eff_dt > '2019-01-01' and to_date(strt_tms) = '2019-01-10'
)
,res2 as
(
select conf_id, count(distinct c.mktg_id) as num_cpg
from res1 group by conf_id having count(distinct c.mktg_id) > 1
)
select res1.mktg_id, mktg_cd, count(distinct res1.conf_id) from res1 t1 inner join res2 t2 on t1.conf_id=t2.conf_id group by res1.mktg_id, mktg_cd;
If the query is still slow, could you provide table and partition details.
It returns
"invalid identifier" on "pe.partyid" (level 2).
Can you please advise on how to correct?
update table_x pe
set pe.taxidnumber =
(select tin
from (select tin
,version
,max(version) over(partition by partyid) maxversion
from table_y
where partyid = pe.partyid)
where version = maxversion);
In Oracle you can use a table alias in an immediate subquery (one level down), but not in more deeply-nested subqueries.
You can go around this with factored subqueries (WITH clause). But in your case, it's not clear why you need a correlated sub-subquery. Move the WHERE condition on matching by partyid to the middle query; that way the inner-most query will be uncorrelated, so it will be computed just once. Move the partyid check next to version = maxversion.
I would do:
create global temporary table tempt as select tin, partyid from table_y where rownum < 2;
insert into tempt select tin, partyid
from (select tin
,partyid
,version
,max(version) over(partition by partyid) maxversion
from table_y
where version = maxversion);
merge into table_x t
using tempt d
on (t.partyid = d.partyid)
when matched then update set t.tin = d.tin;
I'm sorry for my strange title, but I don't know what exactly I'm looking for. The task is quite simple. I have the table of competitions. Another table groups. In every group there are several contestants. In the last table are stored the results of contestants. The task is to get the first three of the contestants of every group.
So I have to loop through the groups, get the first three contestants (according to achieved points) of every group and append them into some variable.
Here is the pseudocode:
CREATE OR REPLACE PROCEDURE get_first_three_of_all(contestants OUT SOME_TYPE) AS
CURSOR groups SELECT...
BEGIN
FOR group IN groups LOOP
APPEND(contestants, get_first_three_of_one_group(group.id))
END LOOP;
END;
I have no idea, how to solve this task. I even don't know what should I look for. Would you be so kind and help me, please? Thanks.
Edited: simplified structure of my tables:
Competition: competition_id
Contestant: contestant_id
GroupContestant: contestant_group_id, competition_d, group_number, contestant_id
Result: contestant_group_id, juror, points
Select to get data of one group (group number YYY) is here:
SELECT * FROM (
SELECT res.contestant_group_id, SUM(res.points) AS points
FROM Result res
WHERE res.couple_group_id IN (SELECT couple_group_id
FROM GroupContestant
WHERE competition_id = XXX
AND group_number = YYY)
GROUP BY res.contestant_group_id
ORDER BY points DESC
)
WHERE ROWNUM <= 3;
Analytic functions to the rescue. To select top 3 results for each group, each competition:
SELECT * FROM (
SELECT grp.competition_id, grp.group_number, res.contestant_group_id, res.points,
row_number() over (partition by grp.competition_id, grp.group_number
order by res.points desc) rn
FROM (SELECT contestant_group_id, SUM(points) AS points
FROM Result
GROUP BY contestant_group_id) res
JOIN GroupContestant grp ON (grp.contestant_group_id = res.contestant_group_id)
)
WHERE rn <= 3;
Pay attention to how you resolve ties (consider using rank or dense_rank instead of row_number).
You can use RANK() analytic function to achieve the goal:
select *
from (select group_num,
points,
rank() over(partition by group_num order by points desc) rank
from results
inner join group_contestant
using (contestant_group_id))
where rank <= 3
order by group_num, points desc;
Here is SQLFiddle to play with.
I am very new at using Oracle (in the class now). I have a problem with the query I am trying to run. I have researched a lot of other answers on this site and none of them seem to apply directly to my problem so the solutions aren't working.
I need to find the total amount spent on lunches by each employee.
Show first_name, last_name, credit_limit, and total_price_spent in your results.
Order the answer by total_price_spent in descending order. Only show the employees who spent more than their credit limit.
I figured out how to do everything but the part about showing only the employees who spent more than their credit limit. I tried to use a select statement at the end but discovered that I can't use an alias in a select statement so I don't really know where to go from here. Any help would be appreciated. This is what I have so far.
select a.first_name, a.last_name, credit_limit, sum(c.quantity * d.price) as total_price_spent
from l_employees a join l_lunches b on a.employee_id = b.employee_id join l_lunch_items c on b.lunch_id = c.lunch_id join l_foods d on c.supplier_id = d.supplier_id and c.product_code = d.product_code
group by a.first_name, a.last_name, a.credit_limit
order by total_price_spent desc;
As Mike said : Add HAVING
select a.first_name, a.last_name, credit_limit, sum(c.quantity * d.price) as total_price_spent
from l_employees a join l_lunches b on a.employee_id = b.employee_id join l_lunch_items c on b.lunch_id = c.lunch_id join l_foods d on c.supplier_id = d.supplier_id and c.product_code = d.product_code
group by a.first_name, a.last_name, a.credit_limit
having sum(c.quantity * d.price) > credit_limit
order by total_price_spent desc;
I think what you're looking for is a HAVING clause. It's like a WHERE, but is used when you're using group by. You want to drop it in between the group by and order by. Something like 'HAVING total > a.credit_limit' should work. If using the alias 'total' doesn't work (haven't tested this), you might have to do 'sum(c.quantity * d.price)' again in the HAVING clause instead of using total, so HAVING sum(c.quantity * d.price) > a.credit_limit.
My subquery returns more than one row and I need the first row and keep my max function
Select ...
Where GHTY_FIRME.FIRME_ID= (Select FIRME_ID
FROM imag_verification_tube
WHERE (numero_dossier = '12004' OR NUMERO_TIRE= '12004')
AND CREE_LE = (select max (CREE_LE)
from tableX where(numero_dossier ='12004' OR
NUMERO_PQDCS= '12004 ')));
Using the rownum pseudocolumn:
Select ...
Where GHTY_FIRME.FIRME_ID= (Select FIRME_ID
FROM imag_verification_tube
WHERE (numero_dossier = '12004' OR NUMERO_TIRE= '12004')
AND CREE_LE = (select max (CREE_LE)
from tableX
where(numero_dossier ='12004'
OR NUMERO_PQDCS= '12004 ')
and rownum < 2));
See also On ROWNUM and Limiting Results.
That said, you can try to optimize the sql. One of the first things I would do is to convert the inner SQLs to joins. Also, depending on your business logic, the or condition could also be elminated.