Is it possible to order the results of an SQL query, on a field that is not in the projection itself?
See example below - I am taking the distinct ID of a product table, but I want it ordered by title. I don't want to include the title because I am using NHibernate to generate a query, and page the results. I am then using this distinct ID resultset, to load the actual results.
SELECT
DISTINCT this_.`ID` AS y0
FROM
`Product` this_
LEFT OUTER JOIN
`Brand` brand3_
ON this_.BrandId=brand3_.ID
INNER JOIN
`Product_CultureInfo` productcul2_
ON this_.ID=productcul2_.ProductID
AND (
(
(
productcul2_.`Deleted` = 0
OR productcul2_.`Deleted` IS NULL
)
AND (
productcul2_.`_Temporary_Flag` = 0
OR productcul2_.`_Temporary_Flag` IS NULL
)
)
)
INNER JOIN
`ProductCategory` aliasprodu1_
ON this_.ID=aliasprodu1_.ProductID
AND (
(
(
aliasprodu1_.`Deleted` = 0
OR aliasprodu1_.`Deleted` IS NULL
)
AND (
aliasprodu1_.`_Temporary_Flag` = 0
OR aliasprodu1_.`_Temporary_Flag` IS NULL
)
)
)
WHERE
(
this_._Temporary_Flag =FALSE
OR this_._Temporary_Flag IS NULL
)
AND this_.Published = TRUE
AND (
this_.Deleted = FALSE
OR this_.Deleted IS NULL
)
AND (
this_._ComputedDeletedValue = FALSE
OR this_._ComputedDeletedValue IS NULL
)
AND (
(
this_._TestItemSessionGuid IS NULL
OR this_._TestItemSessionGuid = ''
)
)
AND (
productcul2_._ActualTitle LIKE '%silver%'
OR brand3_.Title LIKE '%silver%'
OR aliasprodu1_.CategoryId IN (
47906817 , 47906818 , 47906819 , 47906816 , 7012353 , 44662785
)
)
AND this_.Published = TRUE
AND this_.Published = TRUE
ORDER BY
this_.Priority ASC,
productcul2_._ActualTitle ASC,
this_.Priority ASC LIMIT 25;
Don't know if there's a better solution but how about a nested select where the external query exlude the field that you're not interested in?
So, something like that on a "random" table
SELECT a,b,c from (SELECT a,b,c,d from myTable order by d)
Obviously if there is a "language-direct" solution will be better because, in that way, you have to do two projection and one of those is useless
Related
I have created a search SQL query, I'm almost finished I only need to match the WHERE clause with an id and it's parent ids. Currently I only match with an id and not it's parents. I'm not sure how to solve this.
This is my query, the code where I need the change is where the comment "This part needs to match the tileid and it's parent tileids" is. Based on the [TileId] I need to get the [TileId] and it's parents.
WITH [TileSearch_CTE] ([TileId], [TypeId], [TypeName], [Title], [Info]) AS
(
SELECT TOP 10 [TileId], [TypeId], [TypeName], [Title], [Info]
FROM [Priox].[TileFullTextSearchNL]
INNER JOIN CONTAINSTABLE([Priox].[TileFullTextSearchNL], *, '"searchText*"') AS [CT]
ON [Priox].[TileFullTextSearchNL].[TileId] = [CT].[Key]
WHERE
(
NOT EXISTS
(
SELECT [intPortalTileFilterId]
FROM [Priox].[tblPortalTileFilter]
WHERE [intPortalTileIdFk] = [TileId] -- This part needs to match the tileid and it's parent tileids
)
OR EXISTS
(
SELECT [intPortalTileFilterId]
FROM [Priox].[tblPortalTileFilter]
WHERE [intPortalTileIdFk] = [TileId] -- This part needs to match the tileid and it's parent tileids
AND [intPortalFilterIdFk] IN (56)
)
)
ORDER BY [CT].[Rank] DESC
)
SELECT [TileId], [TypeName], [Title], [Info], [TP].[strName] AS [ParamName], [TPV].[strParamValue] AS [ParamValue]
FROM [TileSearch_CTE]
LEFT JOIN [Priox].[tblPortalTileParam] AS [TP] ON [TP].[intTileType] = [TileSearch_CTE].[TypeId]
LEFT JOIN [Priox].[tblPortalTileParamValue] AS [TPV] ON [TPV].[intTileParamIdFk] = [TP].[intPortalTileParamId] AND [TileSearch_CTE].[TileId] = [TPV].[intTileIdFk]
This is the database structure of the tiles.
So the query should do something like this.
SELECT [intPortalTileFilterId]
FROM [Priox].[tblPortalTileFilter]
WHERE [intPortalTileIdFk] IN (438,1317)
I fixed it myself, created a function that returns the parents and the child.
CREATE FUNCTION [Priox].[GetTileIdHierarchy]
(
#tileId int
)
RETURNS TABLE
AS
RETURN
(
WITH parents AS
(
SELECT [intPortalTileId], [intPortalTileId] AS [intParentIdFk]
FROM [Priox].[tblPortalTile] WHERE [intPortalTileId] = #tileId
UNION ALL
SELECT p.[intPortalTileId], [Priox].[tblPortalTile].[intParentIdFk]
FROM parents p
INNER JOIN [Priox].[tblPortalTile] on p.[intParentIdFk] = [Priox].[tblPortalTile].[intPortalTileId]
AND [Priox].[tblPortalTile].[intParentIdFk] IS NOT NULL
AND [Priox].[tblPortalTile].[intPortalTileId] <> [Priox].[tblPortalTile].[intParentIdFk]
)
SELECT [intPortalTileId], [intParentIdFk]
FROM parents
WHERE [intPortalTileId] = #tileId
)
GO
And changed my search query accordingly.
WITH [TileSearch_CTE] ([TileId], [TypeId], [TypeName], [Title], [Info], [Rank]) AS
(
SELECT TOP 10 [TileId], [TypeId], [TypeName], [Title], [Info],[CT].[Rank] AS [Rank]
FROM [Priox].[TileFullTextSearchNL]
INNER JOIN CONTAINSTABLE([Priox].[TileFullTextSearchNL], *, '"searchTerm*"') AS [CT]
ON [Priox].[TileFullTextSearchNL].[TileId] = [CT].[Key]
WHERE
(
NOT EXISTS
(
SELECT [intPortalTileFilterId]
FROM [Priox].[tblPortalTileFilter]
WHERE [intPortalTileIdFk] IN
(
SELECT [intParentIdFk] FROM [Priox].[GetTileIdHierarchy] ([TileId])
)
)
OR
EXISTS
(
SELECT [intPortalTileFilterId]
FROM [Priox].[tblPortalTileFilter]
WHERE [intPortalTileIdFk] IN
(
SELECT [intParentIdFk] FROM [Priox].[GetTileIdHierarchy] ([TileId])
)
AND [intPortalFilterIdFk] IN (51)
)
)
ORDER BY [CT].[Rank] DESC
)
SELECT [TileId], [TypeName], [Title], [Info], [TP].[strName] AS [ParamName], [TPV].[strParamValue] AS [ParamValue] , [Rank]
FROM [TileSearch_CTE]
LEFT JOIN [Priox].[tblPortalTileParam] AS [TP] ON [TP].[intTileType] = [TileSearch_CTE].[TypeId]
LEFT JOIN [Priox].[tblPortalTileParamValue] AS [TPV] ON [TPV].[intTileParamIdFk] = [TP].[intPortalTileParamId] AND [TileSearch_CTE].[TileId] = [TPV].[intTileIdFk]
I edited the starting post with the solution.
Microsoft has deprecated GROUP BY ALL and while the query might work now, I'd like to future-proof this query for future SQL upgrades.
Currently, my query is:
SELECT qt.QueueName AS [Queue] ,
COUNT ( qt.QueueName ) AS [#ofUnprocessedEnvelopes] ,
COUNT ( CASE WHEN dq.AssignedToUserID = 0 THEN 1
ELSE NULL
END
) AS [#ofUnassignedEnvelopes] ,
MIN ( dq.DocumentDate ) AS [OldestEnvelope]
FROM dbo.VehicleReg_Documents_QueueTypes AS [qt]
LEFT OUTER JOIN dbo.VehicleReg_Documents_Queue AS [dq] ON dq.QueueID = qt.QueueTypeID
WHERE dq.IsProcessed = 0
AND dq.PageNumber = 1
GROUP BY ALL qt.QueueName
ORDER BY qt.QueueName ASC;
And the resulting data set:
<table><tbody><tr><td>Queue</td><td>#ofUnprocessedEnvelopes</td><td>#ofUnassignedEnvelopes</td><td>OldestEnvelope</td></tr><tr><td>Cancellations</td><td>0</td><td>0</td><td>NULL</td></tr><tr><td>Dealer</td><td>26</td><td>17</td><td>2018-04-06</td></tr><tr><td>Matched to Registration</td><td>93</td><td>82</td><td>2018-04-04</td></tr><tr><td>New Registration</td><td>166</td><td>140</td><td>2018-03-21</td></tr><tr><td>Remaining Documents</td><td>2</td><td>2</td><td>2018-04-04</td></tr><tr><td>Renewals</td><td>217</td><td>0</td><td>2018-04-03</td></tr><tr><td>Transfers</td><td>296</td><td>245</td><td>2018-03-30</td></tr><tr><td>Writebacks</td><td>53</td><td>46</td><td>2018-04-09</td></tr></tbody></table>
I've tried various versions using CTE's and UNION's but I cannot get result set to generate correctly - the records that have no counts will not display or I will have duplicate records displayed.
Any suggestions on how to make this work without the GROUP BY ALL?
Below is one attempt where I tried a CTE with a UNION:
;WITH QueueTypes ( QueueTypeID, QueueName )
AS ( SELECT QueueTypeID ,
QueueName
FROM dbo.VehicleReg_Documents_QueueTypes )
SELECT qt.QueueName AS [Queue] ,
COUNT ( qt.QueueName ) AS [#ofUnprocessedEnvelopes] ,
COUNT ( CASE WHEN dq.AssignedToUserID = 0 THEN 1
ELSE NULL
END
) AS [#ofUnassignedEnvelopes] ,
CONVERT ( VARCHAR (8), MIN ( dq.DocumentDate ), 1 ) AS [OldestEnvelope]
FROM QueueTypes AS qt
LEFT OUTER JOIN dbo.VehicleReg_Documents_Queue AS dq ON dq.QueueID = qt.QueueTypeID
WHERE dq.IsProcessed = 0
AND dq.PageNumber = 1
GROUP BY qt.QueueName
UNION ALL
SELECT qt.QueueName AS [Queue] ,
COUNT ( qt.QueueName ) AS [#ofUnprocessedEnvelopes] ,
COUNT ( CASE WHEN dq.AssignedToUserID = 0 THEN 1
ELSE NULL
END
) AS [#ofUnassignedEnvelopes] ,
CONVERT ( VARCHAR (8), MIN ( dq.DocumentDate ), 1 ) AS [OldestEnvelope]
FROM QueueTypes AS qt
LEFT OUTER JOIN dbo.VehicleReg_Documents_Queue AS dq ON dq.QueueID = qt.QueueTypeID
GROUP BY qt.QueueName
But the results are not close to being correct:
Your current query doesn't work as it seems to work, because while you outer join table VehicleReg_Documents_Queue you dismiss all outer joined rows in the WHERE clause, so you are where you would have been with a mere inner join. You may want to consider either moving your criteria to the ON clause or make this an inner join right away.
It is also weird that you join queue type and queue not on the queue ID or the queue type ID, but on dq.QueueID = qt.QueueTypeID. That's like joining employees and addresses on employee number matching the house number. At least that's what it looks like.
(Then why does your queue type table have a queue name? Shouldn't the queue table contain the queue name instead? But this is not about your query, but about your data model.)
GROUP BY ALL means: "Please give us all QueueNames, even when the WHERE clause dismisses them. I see two possibilities for your query:
You do want an outer join actually. Then there is no WHERE clause and you can simply make this GROUP BY qt.QueueName.
You don't want an outer join. Then we want a row per QueueName in the table, which we might not get with simply changing GROUP BY ALL qt.QueueName to GROUP BY qt.QueueName.
In that second case we want all QueueNames first and outer join your query:
select
qn.QueueName AS [Queue],
q.[#ofUnassignedEnvelopes],
q.[OldestEnvelope]
FROM (select distinct QueueName from VehicleReg_Documents_QueueTypes) qn
LEFT JOIN
(
SELECT qt.QueueName,
COUNT ( qt.QueueName ) AS [#ofUnprocessedEnvelopes] ,
COUNT ( CASE WHEN dq.AssignedToUserID = 0 THEN 1
ELSE NULL
END
) AS [#ofUnassignedEnvelopes] ,
MIN ( dq.DocumentDate ) AS [OldestEnvelope]
FROM dbo.VehicleReg_Documents_QueueTypes AS [qt]
JOIN dbo.VehicleReg_Documents_Queue AS [dq] ON dq.QueueID = qt.QueueTypeID
WHERE dq.IsProcessed = 0
AND dq.PageNumber = 1
) q ON q.QueueName = qn.QueueName
GROUP BY ALL qn.QueueName
ORDER BY qn.QueueName ASC;
I think the best corollary here for a 'GROUP BY ALL' into something more ANSI compliant would be a CASE statement. Without knowing your data, it's hard to say for sure if this is 1:1, but I'm betting it's in the ballpark.
SELECT qt.QueueName AS [Queue]
,COUNT(CASE
WHEN dq.IsProcessed = 0
AND dq.PageNumber = 1
THEN qt.QueueName
END) AS [#ofUnprocessedEnvelopes]
,COUNT(CASE
WHEN dq.AssignedToUserID = 0
AND dq.IsProcessed = 0
AND dq.PageNumber = 1
THEN 1
ELSE NULL
END) AS [#ofUnassignedEnvelopes]
,MIN(CASE
WHEN dq.IsProcessed = 0
AND dq.PageNumber = 1
THEN dq.DocumentDate
END) AS [OldestEnvelope]
FROM dbo.VehicleReg_Documents_QueueTypes AS [qt]
LEFT OUTER JOIN dbo.VehicleReg_Documents_Queue AS [dq] ON dq.QueueID = qt.QueueTypeID
GROUP BY qt.QueueName
ORDER BY qt.QueueName ASC;
That's a bit uglier because every aggregate has to have the WHERE conditions inside a case statement, but at least you are future proof.
I'm trying to join three tables to pull back a list of distinct blog posts with associated assets (images etc) but I keep coming up a cropper. The three tablets are tblBlog, tblAssetLink and tblAssets. The Blog tablet hold the blog, the asset table holds the assets and the Assetlink table links the two together.
tblBlog.BID is the PK in blog, tblAssets.AID is the PK in Assets.
This query works but pulls back multiple posts for the same record. I've tried to use select distinct and group by and even union but as my knowledge is pretty poor with SQL - they all error.
I'd like to also discount any assets that are marked as deleted (tblAssets.Deleted = true) but not hide the associated Blog post (if that's not marked as deleted). If anyone can help - it would be much appreciated! Thanks.
Here's my query so far....
SELECT dbo.tblBlog.BID,
dbo.tblBlog.DateAdded,
dbo.tblBlog.PMonthName,
dbo.tblBlog.PDay,
dbo.tblBlog.Header,
dbo.tblBlog.AddedBy,
dbo.tblBlog.PContent,
dbo.tblBlog.Category,
dbo.tblBlog.Deleted,
dbo.tblBlog.Intro,
dbo.tblBlog.Tags,
dbo.tblAssets.Name,
dbo.tblAssets.Description,
dbo.tblAssets.Location,
dbo.tblAssets.Deleted AS Expr1,
dbo.tblAssetLink.Priority
FROM dbo.tblBlog
LEFT OUTER JOIN dbo.tblAssetLink
ON dbo.tblBlog.BID = dbo.tblAssetLink.BID
LEFT OUTER JOIN dbo.tblAssets
ON dbo.tblAssetLink.AID = dbo.tblAssets.AID
WHERE ( dbo.tblBlog.Deleted = 'False' )
ORDER BY dbo.tblAssetLink.Priority, tblBlog.DateAdded DESC
EDIT
Changed the Where and the order by....
Expected output:
tblBlog.BID = 123
tblBlog.DateAdded = 12/04/2015
tblBlog.Header = This is a header
tblBlog.AddedBy = Persons name
tblBlog.PContent = *text*
tblBlog.Category = Category name
tblBlog.Deleted = False
tblBlog.Intro = *text*
tblBlog.Tags = Tag, Tag, Tag
tblAssets.Name = some.jpg
tblAssets.Description = Asset desc
tblAssets.Location = Location name
tblAssets.Priority = True
Use OUTER APPLY:
DECLARE #b TABLE ( BID INT )
DECLARE #a TABLE ( AID INT )
DECLARE #ba TABLE
(
BID INT ,
AID INT ,
Priority INT
)
INSERT INTO #b
VALUES ( 1 ),
( 2 )
INSERT INTO #a
VALUES ( 1 ),
( 2 ),
( 3 ),
( 4 )
INSERT INTO #ba
VALUES ( 1, 1, 1 ),
( 1, 2, 2 ),
( 2, 1, 1 ),
( 2, 2, 2 )
SELECT *
FROM #b b
OUTER APPLY ( SELECT TOP 1
a.*
FROM #ba ba
JOIN #a a ON a.AID = ba.AID
WHERE ba.BID = b.BID
ORDER BY Priority
) o
Output:
BID AID
1 1
2 1
Something like:
SELECT b.BID ,
b.DateAdded ,
b.PMonthName ,
b.PDay ,
b.Header ,
b.AddedBy ,
b.PContent ,
b.Category ,
b.Deleted ,
b.Intro ,
b.Tags ,
o.Name ,
o.Description ,
o.Location ,
o.Deleted AS Expr1 ,
o.Priority
FROM dbo.tblBlog b
OUTER APPLY ( SELECT TOP 1
a.* ,
al.Priority
FROM dbo.tblAssetLink al
JOIN dbo.tblAssets a ON al.AID = a.AID
WHERE b.BID = al.BID
ORDER BY al.Priority
) o
WHERE b.Deleted = 'False'
You cannot join three tables unless they all have the same attribute. It would work if all tables had BID, but the second join is trying to join AID. Which wont work. They all have to have BID.
Based on your comments
i would like to get is just one asset per blog post (top one ordered
by Priority)
You can change your query as following. I suggest changing the join with dbo.tblAssetLink to filtered one, which contains only one (highest priority) link for every blog.
SELECT dbo.tblBlog.BID,
dbo.tblBlog.DateAdded,
dbo.tblBlog.PMonthName,
dbo.tblBlog.PDay,
dbo.tblBlog.Header,
dbo.tblBlog.AddedBy,
dbo.tblBlog.PContent,
dbo.tblBlog.Category,
dbo.tblBlog.Deleted,
dbo.tblBlog.Intro,
dbo.tblBlog.Tags,
dbo.tblAssets.Name,
dbo.tblAssets.Description,
dbo.tblAssets.Location,
dbo.tblAssets.Deleted AS Expr1,
dbo.tblAssetLink.Priority
FROM dbo.tblBlog
LEFT OUTER JOIN
(SELECT BID, AID,
ROW_NUMBER() OVER (PARTITION BY BID ORDER BY [Priority] DESC) as N
FROM dbo.tblAssetLink) AS filteredAssetLink
ON dbo.tblBlog.BID = filteredAssetLink.BID
LEFT OUTER JOIN dbo.tblAssets
ON filteredAssetLink.AID = dbo.tblAssets.AID
WHERE dbo.tblBlog.Deleted = 'False' AND filteredAssetLink.N = 1
ORDER BY tblBlog.DateAdded DESC
The following script is very slow when its run.
I have no idea how to improve the performance of the script.
Even with a view takes more than quite a lot minutes.
Any idea please share to me.
SELECT DISTINCT
( id )
FROM ( SELECT DISTINCT
ct.id AS id
FROM [Customer].[dbo].[Contact] ct
LEFT JOIN [Customer].[dbo].[Customer_ids] hnci ON ct.id = hnci.contact_id
WHERE hnci.customer_id IN (
SELECT DISTINCT
( [Customer_ID] )
FROM [Transactions].[dbo].[Transaction_Header]
WHERE actual_transaction_date > '20120218' )
UNION
SELECT DISTINCT
contact_id AS id
FROM [Customer].[dbo].[Restaurant_Attendance]
WHERE ( created > '2012-02-18 00:00:00.000'
OR modified > '2012-02-18 00:00:00.000'
)
AND ( [Fifth_Floor_London] = 1
OR [Fourth_Floor_Leeds] = 1
OR [Second_Floor_Bristol] = 1
)
UNION
SELECT DISTINCT
( ct.id )
FROM [Customer].[dbo].[Contact] ct
INNER JOIN [Customer].[dbo].[Wifinity_Devices] wfd ON ct.wifinity_uniqueID = wfd.[CustomerUniqueID]
AND startconnection > '2012-02-17'
UNION
SELECT DISTINCT
comdt.id AS id
FROM [Customer].[dbo].[Complete_dataset] comdt
LEFT JOIN [Customer].[dbo].[Aggregate_Spend_Counts] agsc ON comdt.id = agsc.contact_id
WHERE agsc.contact_id IS NULL
AND ( opt_out_Mail <> 1
OR opt_out_email <> 1
OR opt_out_SMS <> 1
OR opt_out_Mail IS NULL
OR opt_out_email IS NULL
OR opt_out_SMS IS NULL
)
AND ( address_1 IS NOT NULL
OR email IS NOT NULL
OR mobile IS NOT NULL
)
UNION
SELECT DISTINCT
( contact_id ) AS id
FROM [Customer].[dbo].[VIP_Card_Holders]
WHERE VIP_Card_number IS NOT NULL
) AS tbl
Wow, where to start...
--this distinct does nothing. Union is already distinct
--SELECT DISTINCT
-- ( id )
--FROM (
SELECT DISTINCT [Customer_ID] as ID
FROM [Transactions].[dbo].[Transaction_Header]
where actual_transaction_date > '20120218' )
UNION
SELECT
contact_id AS id
FROM [Customer].[dbo].[Restaurant_Attendance]
-- not sure that you are getting the date range you want. Should these be >=
-- if you want everything that occurred on the 18th or after you want >= '2012-02-18 00:00:00.000'
-- if you want everything that occurred on the 19th or after you want >= '2012-02-19 00:00:00.000'
-- the way you have it now, you will get everything on the 18th unless it happened exactly at midnight
WHERE ( created > '2012-02-18 00:00:00.000'
OR modified > '2012-02-18 00:00:00.000'
)
AND ( [Fifth_Floor_London] = 1
OR [Fourth_Floor_Leeds] = 1
OR [Second_Floor_Bristol] = 1
)
-- all of this does nothing because we already have every id in the contact table from the first query
-- UNION
-- SELECT
-- ( ct.id )
-- FROM [Customer].[dbo].[Contact] ct
-- INNER JOIN [Customer].[dbo].[Wifinity_Devices] wfd ON ct.wifinity_uniqueID = wfd.[CustomerUniqueID]
-- AND startconnection > '2012-02-17'
UNION
-- cleaned this up with isnull function and coalesce
SELECT
comdt.id AS id
FROM [Customer].[dbo].[Complete_dataset] comdt
LEFT JOIN [Customer].[dbo].[Aggregate_Spend_Counts] agsc ON comdt.id = agsc.contact_id
WHERE agsc.contact_id IS NULL
AND ( isnull(opt_out_Mail,0) <> 1
OR isnull(opt_out_email,0) <> 1
OR isnull(opt_out_SMS,0) <> 1
)
AND coalesce(address_1 , email, mobile) IS NOT NULL
UNION
SELECT
( contact_id ) AS id
FROM [Customer].[dbo].[VIP_Card_Holders]
WHERE VIP_Card_number IS NOT NULL
-- ) AS tbl
Where exists is generally faster than in as well.
Or conditions are generally slower as well, use more union statements instead.
And learn to use left joins correctly. If you have a where condition (other than where id is null) on the table on teh right side of a left join, it will convert to an inner join. If this is not what you want, then your code is currently giving you an incorrect result set.
See http://wiki.lessthandot.com/index.php/WHERE_conditions_on_a_LEFT_JOIN for an explanation of how to fix.
As stated in a comment optimize one at a time. See which one takes the longest and focus on that one.
union will remove duplicates so you don't need the distinct on the individual queries
On you first I would try this:
The left join is killed by the WHERE hnci.customer_id IN so you might as well have a join.
The sub-query is not efficient as cannot use an index on the IN.
The query optimizer does not know what in ( select .. ) will return so it cannot optimize use of indexes.
SELECT ct.id AS id
FROM [Customer].[dbo].[Contact] ct
JOIN [Customer].[dbo].[Customer_ids] hnci
ON ct.id = hnci.contact_id
JOIN [Transactions].[dbo].[Transaction_Header] th
on hnci.customer_id = th.[Customer_ID]
and th.actual_transaction_date > '20120218'
On that second join the query optimizer has the opportunity of which condition to apply first. Let say [Customer].[dbo].[Customer_ids].[customer_id] and [Transactions].[dbo].[Transaction_Header] each have indexes. The query optimizer has the option to apply that before [Transactions].[dbo].[Transaction_Header].[actual_transaction_date].
If [actual_transaction_date] is not indexed then for sure it would do the other ID join first.
With your in ( select ... ) the query optimizer has no option but to apply the actual_transaction_date > '20120218' first. OK some times query optimizer is smart enough to use an index inside the in outside the in but why make it hard for the query optimizer. I have found the query optimizer make better decisions if you make the decisions easier.
A join on a sub-query has the same problem. You take options away from the query optimizer. Give the query optimizer room to breathe.
try this, temptable should help you:
IF OBJECT_ID('Tempdb..#Temp1') IS NOT NULL
DROP TABLE #Temp1
--Low perfomance because of using "WHERE hnci.customer_id IN ( .... ) " - loop join must be
--and this "where" condition will apply to two tables after left join,
--so result will be same as with two inner joints but with bad perfomance
--SELECT DISTINCT
-- ct.id AS id
--INTO #temp1
--FROM [Customer].[dbo].[Contact] ct
-- LEFT JOIN [Customer].[dbo].[Customer_ids] hnci ON ct.id = hnci.contact_id
--WHERE hnci.customer_id IN (
-- SELECT DISTINCT
-- ( [Customer_ID] )
-- FROM [Transactions].[dbo].[Transaction_Header]
-- WHERE actual_transaction_date > '20120218' )
--------------------------------------------------------------------------------
--this will give the same result but with better perfomance then previouse one
--------------------------------------------------------------------------------
SELECT DISTINCT
ct.id AS id
INTO #temp1
FROM [Customer].[dbo].[Contact] ct
JOIN [Customer].[dbo].[Customer_ids] hnci ON ct.id = hnci.contact_id
JOIN ( SELECT DISTINCT
( [Customer_ID] )
FROM [Transactions].[dbo].[Transaction_Header]
WHERE actual_transaction_date > '20120218'
) T ON hnci.customer_id = T.[Customer_ID]
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
INSERT INTO #temp1
( id
)
SELECT DISTINCT
contact_id AS id
FROM [Customer].[dbo].[Restaurant_Attendance]
WHERE ( created > '2012-02-18 00:00:00.000'
OR modified > '2012-02-18 00:00:00.000'
)
AND ( [Fifth_Floor_London] = 1
OR [Fourth_Floor_Leeds] = 1
OR [Second_Floor_Bristol] = 1
)
INSERT INTO #temp1
( id
)
SELECT DISTINCT
( ct.id )
FROM [Customer].[dbo].[Contact] ct
INNER JOIN [Customer].[dbo].[Wifinity_Devices] wfd ON ct.wifinity_uniqueID = wfd.[CustomerUniqueID]
AND startconnection > '2012-02-17'
INSERT INTO #temp1
( id
)
SELECT DISTINCT
comdt.id AS id
FROM [Customer].[dbo].[Complete_dataset] comdt
LEFT JOIN [Customer].[dbo].[Aggregate_Spend_Counts] agsc ON comdt.id = agsc.contact_id
WHERE agsc.contact_id IS NULL
AND ( opt_out_Mail <> 1
OR opt_out_email <> 1
OR opt_out_SMS <> 1
OR opt_out_Mail IS NULL
OR opt_out_email IS NULL
OR opt_out_SMS IS NULL
)
AND ( address_1 IS NOT NULL
OR email IS NOT NULL
OR mobile IS NOT NULL
)
INSERT INTO #temp1
( id
)
SELECT DISTINCT
( contact_id ) AS id
FROM [Customer].[dbo].[VIP_Card_Holders]
WHERE VIP_Card_number IS NOT NULL
SELECT DISTINCT
id
FROM #temp1 AS T
Suppose I have this query
SELECT * FROM (
SELECT * FROM table_a
WHERE id > 10 )
AS a_results LEFT JOIN
(SELECT * from table_b
WHERE id IN
(SElECT id FROM a_results)
ON (a_results.id = b_results.id)
I would get the error "a_results is not a table". Anywhere I could use the re-use the results of the subquery?
Edit: It has been noted that this query doesn't make sense...it doesn't, yes. This is just to illustrate the question which I am asking; the 'real' query actually looks something like this:
SELECT SQL_CALC_FOUND_ROWS * FROM
( SELECT wp_pod_tbl_hotel . *
FROM wp_pod_tbl_hotel, wp_pod_rel, wp_pod
WHERE wp_pod_rel.field_id =12
AND wp_pod_rel.tbl_row_id =1
AND wp_pod.tbl_row_id = wp_pod_tbl_hotel.id
AND wp_pod_rel.pod_id = wp_pod.id
) as
found_hotel LEFT JOIN (
SELECT COUNT(*) as review_count, avg( (
location_rating + staff_performance_rating + condition_rating + room_comfort_rating + food_rating + value_rating
) /6 ) AS average_score, hotelid
FROM (
SELECT r. * , wp_pod_rel.tbl_row_id AS hotelid
FROM wp_pod_tbl_review r, wp_pod_rel, wp_pod
WHERE wp_pod_rel.field_id =11
AND wp_pod_rel.pod_id = wp_pod.id
AND r.id = wp_pod.tbl_row_id
AND wp_pod_rel.tbl_row_id
IN (
SELECT wp_pod_tbl_hotel .id
FROM wp_pod_tbl_hotel, wp_pod_rel, wp_pod
WHERE wp_pod_rel.field_id =12
AND wp_pod_rel.tbl_row_id =1
AND wp_pod.tbl_row_id = wp_pod_tbl_hotel.id
AND wp_pod_rel.pod_id = wp_pod.id
)
) AS hotel_reviews
GROUP BY hotel_reviews.hotelid
ORDER BY average_score DESC
AS sorted_hotel ON (id = sorted_hotel.hotelid)
As you can see, the sub-query which makes up the found_query table is repeated elsewhere downward as another sub-query, so I was hoping to re-use the results
You can not use a sub-query like this.
I'm not sure I understand your query, but wouldn't that be sufficient?
SELECT * FROM table_a a
LEFT JOIN table_b b ON ( b.id = a.id )
WHERE a.id > 10
It would return all rows from table_a where id > 10 and LEFT JOIN rows from table_b where id matches.