Hi I have a CTE with 5 inner joins and a where clause which is reducing by one.
the sample code looks like below. but the actual code has more complex logic
;With CTE_EG AS
(
select *,
-1 as offset from a
inner join a1 on a1.id=a.id
inner join a2 on a1.id=a2.id
inner join a3 on a1.id=a3.id
where a1.offset = a2.quarter-1
union all
select *,
-2 as offset from a
inner join a1 on a1.id=a.id
inner join a2 on a1.id=a2.id
inner join a3 on a1.id=a3.id
where a1.offset = a2.quarter-2
union all
...
)
this repeats till offset -4 and a1.offset = a2.quarter-4.
How can I avoid the same code to be repeated for so many times for only one where clause value. the actualy query has 5 inner joins and total 5 union all.
I can not remove the union all because that will generate in some calculation discrepancy.
I want something like when we pass an integer value n , the selects in between union all should repeat with the changing where clause like a1.offset = a2.quarter-2 to a1.offset = a2.quarter-n
Please suggest
This should just be:
;With Numbers(n) as (
select 1 union all select 2 union all
select 3 union all select 4
), CTE_EG AS
(
select *,
-n as offset from a
inner join a1 on a1.id=a.id
inner join a2 on a1.id=a2.id
inner join a3 on a1.id=a3.id
inner join numbers n on a1.offset = a2.quarter-n
)
I don't understand your point about not being able to remove the UNION ALL.
Related
Im currently trying to combine 2 queries results in one.
These 2 queries has the same number of rows and are group by the same field but has different column.
This works :
SELECT Distinct
MAX(d.libelle) AS libelle_dpt,
MAX(d.code_dpt) AS code_dep,
MAX(r.libelle) AS libelle_region,
MAX(pd.pop_dep) AS nb_habitants,MAX(ls.nb_canton) AS nb_canton
FROM election_2015.commune c
LEFT JOIN (
SELECT MAX(c.code_canton) AS code_canton,Count(distinct c.code_canton) AS nb_canton
FROM election_2015.commune co
JOIN election_2015.departement d
ON co.code_dpt = d.code_dpt
JOIN election_2015.canton c
ON c.code_canton = co.code_canton
GROUP BY d.code_dpt
ORDER BY d.code_dpt ASC
) ls
ON ls.code_canton = c.code_canton
JOIN election_2015.departement d
ON d.code_dpt = c.code_dpt
JOIN election_2015.region r
ON d.code_region = r.code_region
JOIN election.popgent_all pd
ON pd.dep = d.code_dpt
GROUP BY d.code_dpt
But I was wondering if there is an other way to do this, maybe like an union but with rows?
Something like this (not working cause queries hasn't the same number of columns) :
SELECT Distinct
MAX(d.libelle) AS libelle_dpt,
MAX(d.id) AS id_dep,MAX(d.code_dpt) AS code_dep,
MAX(r.libelle) AS libelle_region,
MAX(pd.pop_dep) AS nb_habitants
FROM election_2015.commune c
LEFT JOIN election_2015.departement d
ON d.code_dpt = c.code_dpt
LEFT JOIN election_2015.region r
ON d.code_region = r.code_region
LEFT JOIN election.popgent_all pd
ON pd.dep = d.code_dpt
GROUP BY d.code_dpt
UNION
SELECT Count(distinct c.code_canton) AS nb_canton FROM election_2015.commune co
JOIN election_2015.departement d
ON co.code_dpt = d.code_dpt
JOIN election_2015.canton c
ON c.code_canton = co.code_canton
GROUP BY d.code_dpt
ORDER BY election_2015.departement.code_dpt ASC
Thanks for any help.
Alexandre
Below sample query is a part of my main query. I found SORT operator in below query is consuming 30% of the cost.
To avoid SORT, there is need of creation of Indexes. Is there any other way to optimize this code.
SELECT TOP 1 CONVERT( DATE, T_Date) AS T_Date
FROM TableA
WHERE ID = r.ID
AND Status = 3
AND TableA_ID >ISNULL((
SELECT TOP 1 TableA_ID
FROM TableA
WHERE ID = r.ID
AND Status <> 3
ORDER BY T_Date DESC
), 0)
ORDER BY T_Date ASC
Looks like you can use not exists rather than the sorts. I think you'll probably get a better performance boost by use a CTE or derived table instead of the a scalar subquery.
select *
from r ... left outer join
(
select ID, min(t_date) as min_date from TableA t1
where status = 3 and not exists (
select 1 from TableA t2
where t2.ID = t1.ID
and t2.status <> 3 and t2.t_date > t1.t_date
)
group by ID
) as md on md.ID = r.ID ...
or
select *
from r ... left outer join
(
select t1.ID, min(t1.t_date) as min_date
from TableA t1 left outer join TableA t2
on t2.ID = t1.ID and t2.status <> 3
where t1.status = 3 and t1.t_date < t2.t_date
group by t1.ID
having count(t2.ID) = 0
) as md on md.ID = r.ID ...
It also appears that you're relying on an identity column but it's not clear what those values mean. I'm basically ignoring it and using the date column instead.
Try this:
SELECT TOP 1 CONVERT( DATE, T_Date) AS T_Date
FROM TableA a1
LEFT JOIN (
SELECT ID, MAX(TableA_ID) AS MaxAID
FROM TableA
WHERE Status <> 3
GROUP BY ID
) a2 ON a2.ID = a1.ID AND a1.TableA_ID > coalesce(a2.MAXAID,0)
WHERE a1.ID = r.ID AND a1.Status = 3
ORDER BY T_Date ASC
The use of TOP 1 in combination with the unexplained r alias concern me. There's almost certainly a MUCH better way to get this data into your results that doesn't involve doing this in a sub query (unless this is for an APPLY operation).
these are the five given tables
http://i58.tinypic.com/53wcxe.jpg
this is the recomanded result
http://i58.tinypic.com/2vsrts7.jpg
please help how can i write a query to have this result.
no idea how!!!!
SELECT K.* , COUNT (A.Au_ID) AS AnzahlAuftr
FROM Kunde K
LEFT JOIN Auftrag A ON K.Kd_ID = A.Au_Kd_ID
GROUP BY K.Kd_ID,K.Kd_Firma,K.Kd_Strasse,K.Kd_PLZ,K.Kd_Ort
ORDER BY K.Kd_PLZ DESC;
SELECT COUNT (F.F_ID) AS AnzahlFahrt
FROM Fahrten F
RIGHT JOIN Auftrag A ON A.Au_ID = F.F_Au_ID
SELECT SUM (T.Ts_Strecke) AS SumStrecke
FROM Teilstrecke T
LEFT JOIN Fahrten F ON F.F_ID = T.Ts_F_ID
how to join these 3 in one?
Grouping on Strasse etc. is not necessary and can be quite expensive. What about this approach:
SELECT K.*, ISNULL(Au.AnzahlAuftr,0) AS AnzahlAuftr, ISNULL(Au.AnzahlFahrt,0) AS AnzahlFahrt, ISNULL(Au.SumStrecke,0) AS SumStrecke
FROM Kunde K
LEFT OUTER JOIN
(SELECT A.Au_Kd_ID, COUNT(*) AS AnzahlAuftr, SUM(Fa.AnzahlFahrt1) AS AnzahlFahrt, SUM(Fa.SumStrecke2) AS SumStrecke
FROM Auftrag A LEFT OUTER JOIN
(SELECT F.F_Au_ID, COUNT(*) AS AnzahlFahrt1, SUM(Ts.SumStrecke1) AS SumStrecke2
FROM Fahrten F LEFT OUTER JOIN
(SELECT T.Ts_F_ID, SUM(T.Ts_Strecke) AS SumStrecke1
FROM Teilstrecke T
GROUP BY T.Ts_F_ID) AS Ts
ON Ts.Ts_F_ID = F.F_ID
GROUP BY F.F_Au_ID) AS Fa
ON Fa.F_Au_ID = A.Au_ID
GROUP BY A.Au_Kd_ID) AS Au
ON Au.Au_Kd_ID = K.Kd_ID
Totally confused and I have been working at this for 2 hours
I thought restriction on the left side of the join are honored
On this query I am getting [docSVsys].[visibility] 1 and <> 1
I thought this would restrict [docSVsys].[visibility] to 1
select top 1000
[docSVsys].[sID], [docSVsys].[visibility]
,[Table].[sID],[Table].[enumID],[Table].[valueID]
from [docSVsys] with (nolock)
left Join [DocMVenum1] as [Table] with (nolock)
on [docSVsys].[visibility] in (1)
and [Table].[sID] = [docSVsys].[sID]
and [Table].[enumID] = '140'
and [Table].[valueID] in (1,7)
This works
select top 1000
[docSVsys].[sID], [docSVsys].[visibility]
,[Table].[sID],[Table].[enumID],[Table].[valueID]
from [docSVsys] with (nolock)
left Join [DocMVenum1] as [Table] with (nolock)
on [Table].[sID] = [docSVsys].[sID]
and [Table].[enumID] = '140'
and [Table].[valueID] in (1,7)
where [docSVsys].[visibility] in (1)
I am just having a really off day as I had it in my mind the left side honored the join
SELECT *
FROM A
LEFT JOIN B ON Condition
is equivalent to
SELECT *
FROM A
CROSS JOIN B
WHERE Condition
UNION ALL
SELECT A.*, NULL AS B
FROM A
WHERE NOT EXISTS (SELECT * FROM B WHERE Condition)
Some rough pseudo-code...
Note, that all rows from A get through. It's just that the columns from B can be NULL if the join fails for some particular row of A.
Put the filter on docSVsys into the WHERE clause.
LEFT JOINs preserve all rows from the left (first) table, no matter what. The condition in the ON clause is only for matching which rows from the right/second table should be paired with rows from the left/first table.
If you want to exclude some rows from the firs table, use the WHERE clause:
select top 1000
[docSVsys].[sID], [docSVsys].[visibility]
,[Table].[sID],[Table].[enumID],[Table].[valueID]
from [docSVsys] with (nolock)
left Join [DocMVenum1] as [Table] with (nolock)
on [Table].[sID] = [docSVsys].[sID]
and [Table].[enumID] = '140'
and [Table].[valueID] in (1,7)
where [docSVsys].[visibility] in (1)
Let's sat I have a Table 'A' with rows:
A
B
C
D
Is there a simple way to do a cross join that creates
A 1
A 2
A 3
A 4
...
D 1
D 2
D 3
D 4
without creating a second table?
Something like:
SELECT *
FROM A
CROSS JOIN (1,2,3,4)
something like that should work, i guess
select * from A cross join (select 1 union all select 2 union all select 3 union all select 4) as tmp
you will create a second table, but you won't persist it.
The following would work for a table of any size (though I only tested it against 6 rows). It uses the ranking functions available in SQL Server 2005 and up, but the idea should be adaptible to any RDBMS.
SELECT ta.SomeColumn, cj.Ranking
from TableA ta
cross join (select row_number() over (order by SomeColumn) Ranking from TableA) cj
order by ta.SomeColumn, cj.Ranking
You should be able to achieve this via
select * from A cross join
(select 1
union all
select 2
union all
select 3
union all
select 4)