I am currently working on a quick query on Microsoft SQL Server that should return different INSTALLATION that had the MAX amount of EVENTS on the last year.
This is what I got so far but I know that this is not the right way and was hoping for some insight:
SELECT
i.idInstalac, i.nomInstalac, COUNT(e.idEvento) as cantEventos
FROM
Instalacion i, Eventos e
WHERE
i.idInstalac = e.idInstalac
AND YEAR(e.fchEvento) = 2019
GROUP BY
i.idInstalac, i.nomInstalac
HAVING
MAX cantEventos
Thanks
A simple solution is TOP (1) WITH TIES:
SELECT TOP (1) WITH TIES i.idInstalac, i.nomInstalac, COUNT(e.idEvento) as cantEventos
FROM Instalacion i
INNER JOIN Eventos e ON i.idInstalac = e.idInstalac
WHERE e.fchEvento >= '2019-01-01' and e.fchEvento < '2020-01-01'
GROUP BY i.idInstalac,i.nomInstalac
ORDER BY cantEventos DESC
Note that I rewrote your implicit JOIN as an explicit, modern join (with the ON keyword): implicit join is an old syntax that should not be used in new code. I also changed the date filter in the WHERE clause: using date functions on the column is less efficient, and prevents the database from using an existing index
Related
I wrote the following query in SQLite, which works fine, but have found out the office utilizes SAP ASE (Sybase SQL Server) and it does not display the same result there.
select
dm04_maf.mcn,
dm04_maf.wc_cd,
dm04_maf.buno_serno,
max(dm12_maf_note.maf_note) as Last_Note,
dm12_maf_note.note_dttm as Time_of_Note,
dm12_maf_note.orignr
from
dm04_maf
left join
dm12_maf_note on dm04_maf.mcn = dm12_maf_note.mcn
where dm04_maf.ty_maf_cd = 'TD'
group by dm04_maf.mcn
I believe it is not performing group by correctly as it isn't giving me the last note for each mcn (primary key) it is giving me every note for each mcn.
Any guidance for this would be appreciated.
An ANSI compliant group by query will have all non-aggregate columns (from the select/projection list) also in the group by clause. While many RDBMSs will allow non-ANSI compliant group by queries (like in this question), how each RDBMS chooses to process said non-ANSI compliant group by query is up for grabs (ie, there is no guarantee of getting the same result across different RDBMSs).
Some assumptions:
OP mentions wanting to display just the 'last note'; for now we'll assume that max(maf_note) is sufficient to determine the 'last note' for a given mcn value
the other non-aggregate columns (eg, wc_cd, buno_serno, note_dttm and orignr) should come from the same row that produces last note = max(maf_note)`
Since SAP (Sybase) ASE does not support windows functions nor ROW_NUMBER(), one idea would be to use a sub-query to find the 'last note' and then join this into the main query to pull the rest of the desired values, eg:
select dm1.mcn,
dm1.wc_cd,
dm1.buno_serno,
dt.Last_Note,
dmn1.note_dttm as Time_of_Note,
dmn1.orignr
from dm04_maf dm1
left
join dm12_maf_note dmn1
on dm1.mcn = dmn1.mcn
join (select dm2.mcn,
max(dmn2.maf_note) as Last_Note
from dm04_maf dm2
join dm12_maf_note dmn2
on dm2.mcn = dmn2.mcn
where dm2.ty_maf_cd = 'TD'
group by dm2.mcn
) dt
on dm1.mcn = dt.mcn
and dmn1.maf_note = dt.Last_Note
where dm1.ty_maf_cd = 'TD'
NOTES:
the extra dm1.ty_maf_cd = 'TD' is likely redundant; will leave it up to the OP to decide on whether to keep or remove
(obviously) may need to come back and tweak based on validity of the assumptions and/or updates to the question
With ROW_NUMBER() window function:
select t.mcn, t.wc_cd, t.buno_serno,
t.maf_note as Last_Note,
t.note_dttm as Time_of_Note,
t.orignr
from (
select d04.mcn, d04.wc_cd, d04.buno_serno,
d12.maf_note, d12.note_dttm, d12.orignr,
row_number() over (partition by d04.mcn order by d12.maf_note desc) rn
from dm04_maf d04 left join dm12_maf_note d12
on d04.mcn = d12.mcn
where d04.ty_maf_cd = 'TD'
) t
where t.rn = 1
I'm having a problem with a slight ordering anomaly in a legacy web application, and figured I'd start with the back-end SQL query generated by Hibernate with DB2Dialect:
FROM (SELECT inner2_.*,
ROWNUMBER()
OVER(
ORDER BY ORDER OF inner2_) AS rownumber_
FROM (SELECT this_.sohn AS SOHN1_15_11_,
this_.aslc AS ASLC2_15_11_,
this_.cc AS CC3_15_11_,
bb1_.sbn AS SBN1_2_0_,
bb1_.abc AS ABC3_4_5_,
mh2_.smhn AS SMHN1_9_1_,
mh2_.sabc AS SABC3_4_6_,
og8_.sogn AS SOGN1_11_2_,
og8_.sogo AS SOGO3_4_7_,
oc9_.socn AS SOCN_1_13_3_,
oc9_.soco AS SOCO_3_4_8_
FROM ott.oh this_
INNER JOIN ott.bb1_
ON this_.sbn = bb1_.sbn
INNER JOIN ott.mh2_
ON this_.smhn = mh2_.smhn
LEFT OUTER JOIN ott.og og8_
ON this_.sogn = og8_.sogn
LEFT OUTER JOIN ott.oc oc9_
ON this_.socn = oc9_.socn
WHERE ( 1 = 1 )
AND bb1_.sbn = ?
AND mh2_.smhn = ?
FETCH first 200 ROWS only) AS inner2_) AS inner1_
WHERE rownumber_ > 190
ORDER BY rownumber_
What does this query do? I am especially curious about OVER(), which isn't coming up when I google for such a SQL function (but it is an MDX function?).
This query functions in the application to grab the last page of a paginated list that is ordered by a field that doesn't even appear in the query. The query to populate the first page on initial load is different, and its generated SQL does ORDER BY the desired field.
So to get through this I need to understand how the query functions. Takers?
OVER() is part of so called OLAP functions - a good desrciption can be found in the DB2 SQL Cookbook - i.e. available here:
http://www.ids-system.de/images/Downloads/DB2V97CK.PDF
It is a group of really useful functions.
Also good additional stuff
http://www.ibm.com/developerworks/data/library/techarticle/dm-0401kuznetsov/
In the query
cr is customers,
chh? ise customer_pays,
cari_kod is customer code,
cari_unvan1 is customer name
cha_tarihi is date of pay,
cha_meblag is pay amount
The purpose of query, the get the specisified list of customers and their last date for pay and amount of money...
Actually my manager needs more details but the query is very slow and that is why im using only 3 subquery.
The question is how to combine them ?
I have researched about Cte and "with clause" and "subquery in "where " but without luck.
Can anybody have a proposal.
Operating system is win2003 and sql server version is mssql 2005.
Regards
select cr.cari_kod,cr.cari_unvan1, cr.cari_temsilci_kodu,
(select top 1
chh1.cha_tarihi
from dbo.CARI_HESAP_HAREKETLERI chh1 where chh1.cha_kod=cr.cari_kod order by chh1.cha_RECno) as sontar,
(select top 1
chh2.cha_meblag
from dbo.CARI_HESAP_HAREKETLERI chh2 where chh2.cha_kod=cr.cari_kod order by chh2.cha_RECno) as sontutar
from dbo.CARI_HESAPLAR cr
where (select top 1
chh3.cha_tarihi
from dbo.CARI_HESAP_HAREKETLERI chh3 where chh3.cha_kod=cr.cari_kod order by chh3.cha_RECno) >'20130314'
and
cr.cari_bolge_kodu='322'
or
cr.cari_bolge_kodu='324'
order by cr.cari_kod
You will probably speed up the query by changing your last where clause to:
where (select top 1 chh3.cha_tarihi
from dbo.CARI_HESAP_HAREKETLERI chh3 where chh3.cha_kod=cr.cari_kod
order by chh3.cha_RECno
) >'20130314' and
cr.cari_bolge_kodu in ('322', '324')
order by cr.cari_kod
Assuming that you want both the date condition met and one of the two codes. Your original logic is the (date and code = 322) OR (code = 324).
The overall query can be improved by finding the record in the chh table and then just using that. For this, you want to use the window function row_number(). I think this is the query that you want:
select cari_kod, cari_unvan1, cari_temsilci_kodu,
cha_tarihi, cha_meblag
from (select cr.*, chh.*,
ROW_NUMBER() over (partition by chh.cha_kod order by chh.cha_recno) as seqnum
from dbo.CARI_HESAPLAR cr join
dbo.CARI_HESAP_HAREKETLERI chh
on chh.cha_kod=cr.cari_kod
where cr.cari_bolge_kodu in ('322', '324')
) t
where chh3.cha_tarihi > '20130314' and seqnum = 1
order by cr.cari_kod;
This version assumes the revised logic date/code logic.
The inner subquery select might generate an error if there are two columns with the same name in both tables. If so, then just list the columns instead of using *.
I have created a database for an imaginary solicitors, my last query to complete is driving me insane. I need to work out the total a solicitor has made in their career with the company, I have time_spent and rate to multiply and special rate to add. (special rate is a one off charge for corporate contracts so not many cases have them). the best I could come up with is the code below. It does what I want but only displays the solicitors working on a case with a special rate applied to it.
I essentially want it to display the result of the query in a table even if the special rate is NULL.
I have ordered the table to show the highest amount first so i can use ROWNUM to only show the top 10% earners.
CREATE VIEW rich_solicitors AS
SELECT notes.time_spent * rate.rate_amnt + special_rate.s_rate_amnt AS solicitor_made,
notes.case_id
FROM notes,
rate,
solicitor_rate,
solicitor,
case,
contract,
special_rate
WHERE notes.solicitor_id = solicitor.solicitor_id
AND solicitor.solicitor_id = solicitor_rate.solicitor_id
AND solicitor_rate.rate_id = rate.rate_id
AND notes.case_id = case.case_id
AND case.contract_id = contract.contract_id
AND contract.contract_id = special_rate.contract_id
ORDER BY -solicitor_made;
Query:
SELECT *
FROM rich_solicitors
WHERE ROWNUM <= (SELECT COUNT(*)/10
FROM rich_solicitors)
I'm suspicious of your use of ROWNUM in your example query...
Oracle9i+ supports analytic functions, like ROW_NUMBER and NTILE, to make queries like your example easier. Analytics are also ANSI, so the syntax is consistent when implemented (IE: Not on MySQL or SQLite). I re-wrote your query as:
SELECT x.*
FROM (SELECT n.time_spent * r.rate_amnt + COALESCE(spr.s_rate_amnt, 0) AS solicitor_made,
n.case_id,
NTILE(10) OVER (ORDER BY solicitor_made) AS rank
FROM NOTES n
JOIN SOLICITOR s ON s.solicitor_id = n.solicitor_id
JOIN SOLICITOR_RATE sr ON sr.solicitor_id = s.solicitor_id
JOIN RATE r ON r.rate_id = sr.rate_id
JOIN CASE c ON c.case_id = n.case_id
JOIN CONTRACT cntrct ON cntrct.contract_id = c.contract_id
LEFT JOIN SPECIAL_RATE spr ON spr.contract_id = cntrct.contract_id) x
WHERE x.rank = 1
If you're new to SQL, I recommend using ANSI-92 syntax. Your example uses ANSI-89, which doesn't support OUTER JOINs and is considered deprecated. I used a LEFT OUTER JOIN against the SPECIAL_RATE table because not all jobs are likely to have a special rate attached to them.
It's also not recommended to include an ORDER BY in views, because views encapsulate the query -- no one will know what the default ordering is, and will likely include their own (waste of resources potentially).
you need to left join in the special rate.
If I recall the oracle syntax is like:
AND contract.contract_id = special_rate.contract_id (+)
but now special_rate.* can be null so:
+ special_rate.s_rate_amnt
will need to be:
+ coalesce(special_rate.s_rate_amnt,0)
So I decided to try out PostgreSQL instead of MySQL but I am having some slight conversion problems. This was a query of mine that samples data from four tables and spit them out all in on result.
I am at a loss of how to convey this in PostgreSQL and specifically in Django but I am leaving that for another quesiton so bonus points if you can Django-fy it but no worries if you just pure SQL it.
SELECT links.id, links.created, links.url, links.title, user.username, category.title, SUM(votes.karma_delta) AS karma, SUM(IF(votes.user_id = 1, votes.karma_delta, 0)) AS user_vote
FROM links
LEFT OUTER JOIN `users` `user` ON (`links`.`user_id`=`user`.`id`)
LEFT OUTER JOIN `categories` `category` ON (`links`.`category_id`=`category`.`id`)
LEFT OUTER JOIN `votes` `votes` ON (`votes`.`link_id`=`links`.`id`)
WHERE (links.id = votes.link_id)
GROUP BY votes.link_id
ORDER BY (SUM(votes.karma_delta) - 1) / POW((TIMESTAMPDIFF(HOUR, links.created, NOW()) + 2), 1.5) DESC
LIMIT 20
The IF in the select was where my first troubles began. Seems it's an IF true/false THEN stuff ELSE other stuff END IF yet I can't get the syntax right. I tried to use Navicat's SQL builder but it constantly wanted me to place everything I had selected into the GROUP BY and that I think it all kinds of wrong.
What I am looking for in summary is to make this MySQL query work in PostreSQL. Thank you.
Current Progress
Just want to thank everybody for their help. This is what I have so far:
SELECT links_link.id, links_link.created, links_link.url, links_link.title, links_category.title, SUM(links_vote.karma_delta) AS karma, SUM(CASE WHEN links_vote.user_id = 1 THEN links_vote.karma_delta ELSE 0 END) AS user_vote
FROM links_link
LEFT OUTER JOIN auth_user ON (links_link.user_id = auth_user.id)
LEFT OUTER JOIN links_category ON (links_link.category_id = links_category.id)
LEFT OUTER JOIN links_vote ON (links_vote.link_id = links_link.id)
WHERE (links_link.id = links_vote.link_id)
GROUP BY links_link.id, links_link.created, links_link.url, links_link.title, links_category.title
ORDER BY links_link.created DESC
LIMIT 20
I had to make some table name changes and I am still working on my ORDER BY so till then we're just gonna cop out. Thanks again!
Have a look at this link GROUP BY
When GROUP BY is present, it is not
valid for the SELECT list expressions
to refer to ungrouped columns except
within aggregate functions, since
there would be more than one possible
value to return for an ungrouped
column.
You need to include all the select columns in the group by that are not part of the aggregate functions.
A few things:
Drop the backticks
Use a CASE statement instead of IF() CASE WHEN votes.use_id = 1 THEN votes.karma_delta ELSE 0 END
Change your timestampdiff to DATE_TRUNC('hour', now()) - DATE_TRUNC('hour', links.created) (you will need to then count the number of hours in the resulting interval. It would be much easier to compare timestamps)
Fix your GROUP BY and ORDER BY
Try to replace the IF with a case;
SUM(CASE WHEN votes.user_id = 1 THEN votes.karma_delta ELSE 0 END)
You also have to explicitly name every column or calculated column you use in the GROUP BY clause.