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/
Related
I try to find what I missed in the code to retrieve the value of "Last_Maintenance" in a table called "Interventions".
I try to understand the order rules of SQL and the particularities of subqueries without success.
Did I missed something, something basic or an important step?
---Interventions with PkState "Schedule_Visit" with the Last_Maintenance aggregation
SELECT Interventions.ID AS Nro_Inter,
--Interventions.PlacesList AS Nro_Place,
MaintenanceContracts.Num AS Nro_Contract,
Interventions.TentativeDate AS Schedule_Visit,
--MaintenanceContracts.NumberOfVisits AS Number_Visits_Contracts,
--Interventions.VisitNumber AS Visit_Number,
(SELECT MAX(Interventions.AssignmentDate)
FROM Interventions
WHERE PkState = 'AE4B42CF-0003-4796-89F2-2881527DFB26' AND PkMaintenanceContract IS NOT NULL) AS Last_Maintenance --PkState "Maintenance Executed"
FROM Interventions
INNER JOIN MaintenanceContracts ON MaintenanceContracts.Pk = Interventions.PkMaintenanceContract
WHERE PkState = 'AE4B42CF-0000-4796-89F2-2881527ABC26' AND PkMaintenanceContract IS NOT NULL --PkState "Schedule_Visit"
GROUP BY Interventions.AssignmentDate,
Interventions.ID,
Interventions.PlacesList,
MaintenanceContracts.Num,
Interventions.TentativeDate,
MaintenanceContracts.NumberOfVisits,
Interventions.VisitNumber
ORDER BY Nro_Contract
I try to use GROUP BY and HAVING clause in a sub query, I did not succeed. Clearly I am lacking some understanding.
Output
The output of "Last_Maintenance" is the last date of entire contracts in the DB, which is not the desirable output. The desirable output is to know the last date the maintenance was executed for each row, meaning, for each "Nro-Contract". Somehow I need to aggregate like I did below.
In opposition of what mention I did succeed in another table.
In the table Contracts I did had success as you can see.
SELECT
MaintenanceContracts.Num AS Nro_Contract,
MAX(Interventions.AssignmentDate) AS Last_Maintenance
--MaintenanceContracts.Name AS Place
--MaintenanceContracts.StartDate,
--MaintenanceContracts.EndDate
FROM MaintenanceContracts
INNER JOIN Interventions ON Interventions.PkMaintenanceContract = MaintenanceContracts.Pk
WHERE MaintenanceContracts.ActiveContract = 2 OR MaintenanceContracts.ActiveContract = 1 --// 2 = Inactive; 1 = Active
GROUP BY MaintenanceContracts.Num, MaintenanceContracts.Name,
MaintenanceContracts.StartDate,
MaintenanceContracts.EndDate
ORDER BY Nro_Contract
I am struggling to understanding how nested queries works and how I can leverage in a simple manner the queries.
I think you're mixed up in how aggregation works. The MAX function will get a single MAX value over the entire dataset. What you're trying to do is get a MAX for each unique ID. For that, you either use derived tables, subqueries or windowed functions. I'm a fan of using the ROW_NUMBER() function to assign a sequence number. If you do it correctly, you can use that row number to get just the most recent record from a dataset. From your description, it sounds like you always want to have the contract and then get some max values for that contract. If that is the case, then you're second query is closer to what you need. Using windowed functions in derived queries has the added benefit of not having to worry about using the GROUP BY clause. Try this:
SELECT
MaintenanceContracts.Num AS Nro_Contract,
--MaintenanceContracts.Name AS Place
--MaintenanceContracts.StartDate,
--MaintenanceContracts.EndDate
i.AssignmentDate as Last_Maintenance
FROM MaintenanceContracts
INNER JOIN (
SELECT *
--This fuction will order the records for each maintenance contract.
--The most recent intervention will have a row_num = 1
, ROW_NUMBER() OVER(PARTITION BY PkMaintenanceContract ORDER BY AssignmentDate DESC) as row_num
FROM Interventions
) as i
ON i.PkMaintenanceContract = MaintenanceContracts.Pk
AND i.row_num = 1 --Used to get the most recent intervention.
WHERE MaintenanceContracts.ActiveContract = 2
OR MaintenanceContracts.ActiveContract = 1 --// 2 = Inactive; 1 = Active
ORDER BY Nro_Contract
;
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
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)
I have this sql query where I'm trying to use CONTAINS to search the title field.
But I get this error.
"Cannot use a CONTAINS or FREETEXT predicate on column 'Title' because it is not full-text indexed."
The Titles table has been indexed and a CONTAINS works fine with a simple search.
Does anyone know what I'm doing wrong? Are CONTAIN queries not supported with inline queries?
This query is being ran in SQL Server 2008.
SELECT pi.PublisherGUID, pi.Publisher, pi.TitleGUID, pi.Title,
pi.YearsPublished, pi.FrontImage, pi.IssueGUID, pi.IssueNumber,
pi.IssueVariation, pi.IssueNotes, pi.CoverDate, pi.IsForSale
FROM (
SELECT ROW_NUMBER() OVER(ORDER BY PublicIssues.Title,PublicIssues.IssueNumber) AS RowNum,
PublicIssues.PublisherGUID, PublicIssues.Publisher,
PublicIssues.TitleGUID, PublicIssues.Title,
PublicIssues.YearsPublished, PublicIssues.FrontImage,
PublicIssues.IssueGUID, PublicIssues.IssueNumber,
PublicIssues.IssueVariation, PublicIssues.IssueNotes,
PublicIssues.CoverDate, PublicIssues.IsForSale
FROM (SELECT dbo.tblTitles.PublisherGUID, dbo.tblPublishers.Name AS Publisher,
dbo.tblTitles.TitleGUID, dbo.tblTitles.Title,
dbo.tblTitles.YearsPublished, dbo.tblIssues.IssueGUID,
dbo.tblIssues.IssueNumber, dbo.tblIssues.IssueVariation,
dbo.tblIssues.IssueNotes, dbo.tblIssues.CoverDate,
dbo.tblStockIssueImages.FrontImage,
ci_owner.IssueForSale(dbo.tblIssues.IssueGUID) AS IsForSale
FROM dbo.tblStockIssueImages RIGHT OUTER JOIN
dbo.tblIssues ON
dbo.tblStockIssueImages.StockIssueImageGUID = dbo.tblIssues.StockIssueImageGUID
LEFT OUTER JOIN
dbo.tblTitles INNER JOIN
dbo.tblPublishers ON dbo.tblTitles.PublisherGUID = dbo.tblPublishers.PublisherGUID
ON dbo.tblIssues.TitleGUID = dbo.tblTitles.TitleGUID
)
AS PublicIssues
WHERE 1=1 AND CONTAINS(Title,#xTitle)
) AS pi
WHERE RowNum BETWEEN (#xPageNum - 1) * #xPageSize + 1 AND
#xPageNum * #xPageSize ORDER BY pi.Title
Indeed, in the context of PublicIssues, Title is not full-text indexed.
It is indexed in the the table tblTitles.
I think it may be possible to move the CONTAINS predicate inside the expression which defines PublicIssues. Something like the following. However I suspect (with the hint of the 1=1) that the idea is to have various other criteria, and it may not be feasible to have all of them "inside". It being [apparently] dynamic SQL, it may be feasible to craft the query by placing the search criteria in one of the two locations as appropriate.
FROM (SELECT dbo.tblTitles.PublisherGUID, dbo.tblPublishers.Name AS Publisher,
dbo.tblTitles.TitleGUID, dbo.tblTitles.Title,
dbo.tblTitles.YearsPublished, dbo.tblIssues.IssueGUID,
dbo.tblIssues.IssueNumber, dbo.tblIssues.IssueVariation,
dbo.tblIssues.IssueNotes, dbo.tblIssues.CoverDate,
dbo.tblStockIssueImages.FrontImage,
ci_owner.IssueForSale(dbo.tblIssues.IssueGUID) AS IsForSale
FROM dbo.tblStockIssueImages RIGHT OUTER JOIN
dbo.tblIssues ON
dbo.tblStockIssueImages.StockIssueImageGUID = dbo.tblIssues.StockIssueImageGUID
LEFT OUTER JOIN
dbo.tblTitles INNER JOIN
dbo.tblPublishers ON dbo.tblTitles.PublisherGUID = dbo.tblPublishers.PublisherGUID
ON dbo.tblIssues.TitleGUID = dbo.tblTitles.TitleGUID
WHERE CONTAINS(Title,#xTitle) --- this lined moved
)
AS PublicIssues