I am trying to run a SELECT query using LEFT JOIN. I get a COUNT on my second table ( the table on the right side of LEFT JOIN ). This process becomes slightly heavy as the number of records on the second table goes up. My first and second table have a one-to-many relationship. The second table's CampaignId column is a foreign key to the first table's Id. This is a simplified version of my query:
SELECT a.[Id]
,a.CampaignId
,a.[Inserted] AS 'Date'
,COUNT(b.Id) AS 'Received'
FROM [CampaignRun] AS a
LEFT JOIN [CampaignRecipient] AS b
ON a.Id = b.CampaignRunId
GROUP BY
a.[Id], a.CampaignId,a.[Inserted]
HAVING
a.CampaignId = 637
ORDER BY
a.[Inserted] DESC
The number 637 is an example for one the records only.
Is there a way to make this query run faster?
Use a sub-select to calculate Received:
SELECT a.[Id]
,a.CampaignId
,a.[Inserted] AS 'Date'
, (SELECT COUNT(*) FROM [CampaignRecipient] AS b
WHERE a.Id = b.CampaignRunId ) AS 'Received'
FROM [CampaignRun] AS a
WHERE a.CampaignId = 637
ORDER BY a.[Inserted] DESC
You have unneed HAVING clause here, which you can move to WHERE clause
SELECT a.[Id]
,a.CampaignId
,a.[Inserted] AS 'Date'
,COUNT(b.Id) AS 'Received'
FROM [CampaignRun] AS a
LEFT JOIN [CampaignRecipient] AS b
ON a.Id = b.CampaignRunId
WHERE a.CampaignId = 637
GROUP BY a.[Id], a.CampaignId,a.[Inserted]
ORDER BY a.[Inserted] DESC
Also ensure that you have index on foreign key in [CampaignRecipient] table on CampaignRunId column. It's considered a good practice.
Related
I have 3 tables in that 2 tables are master table and 3rd is transaction table. i need to get count from transaction table for each value in other two table without loosing rows in mater table
i need result like below
Table layout for understanding
This is the code i have tried,
select s.status_name, e.machine_group_name, qty = COALESCE(COUNT(e.id),0)
from tbl_status s
left outer JOIN tbl_transaction as e ON e.status_name = s.status_name
group by e.machine_group_name, s.status_name
This is solution i have figured:
select m.machine_group_name, s.status_name, qty = COUNT(e.id) from
tbl_machine_group as m
cross join tbl_status as s
left outer join tbl_transaction as e on e.status_name = s.status_name
and e.machine_group_name = m.machine_group_name
group by m.machine_group_name, s.status_name
order by machine_group_name
select
MC_Group_Name
,Status_Name
,count(1) as [Count of Transaction]
from
tbl_Transaction tbl_3
left join tbl_Machine_Group tbl_1
on tbl_3.MC_Group_Name = tbl_1.MC_Group_Name
left join tbl_Status tbl_2
on tbl_3.Status_Name = tbl_2.Status_Name
group by
MC_Group_Name
,Status_Name
I have this query in MySQL:
SELECT pr.*, pr7.value AS `room_price_high`
FROM `jos_hp_properties` pr
LEFT OUTER JOIN `jos_hp_properties2` pr7 ON pr7.property=pr.id
WHERE pr7.field=23
The jos_hp_properties table has 27 rows but the query only returns one. Based on this question I think it may be because of the WHERE clause. The jos_hp_properties2 table has fields id, property, field, value, where field is a foreign key to a third table (which I don't need to get data from).
Is there a way to select all the rows from the first table, including the value from table #2 where the field is 23 (or NULL if there is no field 23)?
Sure. Move the WHERE condition to the JOIN:
SELECT pr.*, pr7.value AS `room_price_high`
FROM `jos_hp_properties` pr
LEFT JOIN `jos_hp_properties2` pr7
ON pr7.property=pr.id
AND
pr7.field=23
You must place the pr7 criteria in the join, not in the where clause. The where clause works on the entire result set AFTER the join has been performed.
SELECT pr.*, pr7.value AS `room_price_high`
FROM `jos_hp_properties` pr
LEFT OUTER JOIN `jos_hp_properties2` pr7 ON pr7.property=pr.id and pr7.field=23
Try this:
SELECT pr.*, pr7.value AS `room_price_high`
FROM `jos_hp_properties` pr
LEFT OUTER JOIN `jos_hp_properties2` pr7 ON pr7.property=pr.id
WHERE (pr7.field=23 OR pr7.field is null)
You can also use a CTE (Common Table Expression) to do the select, then use the CTE to do the left join..
wrc (parentid, childid) as (
select parentid, childid
from placechild
where relationshipid in (select id from placerelationship where relationship = 'Winter Region Capital')
),
stw (cnid, coid, capid, st_or_te, sid, scid,wcid) as (
select s.cnid, s.coid, s.capid, s.st_or_te, s.sid, s.scid, w.childid
from stcap s
left join wrc w
on s.sid = w.parentid
)
select * from stw
I am retrieving data from table ProductionReportMetrics where I have column NetRate_QuoteID. Then to that result set I need to get Description column.
And in order to get a Description column, I need to join 3 tables:
NetRate_Quote_Insur_Quote
NetRate_Quote_Insur_Quote_Locat
NetRate_Quote_Insur_Quote_Locat_Liabi
But after that my premium is completely off.
What am I doing wrong here?
SELECT QLL.Description,
QLL.ClassCode,
prm.NetRate_QuoteID,
QL.LocationID,
ISNULL(SUM(premium),0) AS NetWrittenPremium,
MONTH(prm.EffectiveDate) AS EffMonth
FROM ProductionReportMetrics prm
LEFT JOIN NetRate_Quote_Insur_Quote Q
ON prm.NetRate_QuoteID = Q.QuoteID
INNER JOIN NetRate_Quote_Insur_Quote_Locat QL
ON Q.QuoteID = QL.QuoteID
INNER JOIN NetRate_Quote_Insur_Quote_Locat_Liabi QLL
ON QL.LocationID = QLL.LocationID
WHERE YEAR(prm.EffectiveDate) = 2016 AND
CompanyLine = 'Ironshore Insurance Company'
GROUP BY MONTH(prm.EffectiveDate),
QLL.Description,
QLL.ClassCode,
prm.NetRate_QuoteID,
QL.LocationID
I think the problem in this table:
What Am I missing in this Query?
select
ClassCode,
QLL.Description,
sum(Premium)
from ProductionReportMetrics prm
LEFT JOIN NetRate_Quote_Insur_Quote Q ON prm.NetRate_QuoteID = Q.QuoteID
LEFT JOIN NetRate_Quote_Insur_Quote_Locat QL ON Q.QuoteID = QL.QuoteID
LEFT JOIN
(SELECT * FROM NetRate_Quote_Insur_Quote_Locat_Liabi nqI
JOIN ( SELECT LocationID, MAX(ClassCode)
FROM NetRate_Quote_Insur_Quote_Locat_Liabi GROUP BY LocationID ) nqA
ON nqA.LocationID = nqI.LocationID ) QLL ON QLL.LocationID = QL.LocationID
where Year(prm.EffectiveDate) = 2016 AND CompanyLine = 'Ironshore Insurance Company'
GROUP BY Q.QuoteID,QL.QuoteID,QL.LocationID
Now it says
Msg 8156, Level 16, State 1, Line 14
The column 'LocationID' was specified multiple times for 'QLL'.
It looks like DVT basically hit on the answer. The only reason you would get different amounts(i.e. duplicated rows) as a result of a join is that one of the joined tables is not a 1:1 relationship with the primary table.
I would suggest you do a quick check against those tables, looking for table counts.
--this should be your baseline count
SELECT COUNT(*)
FROM ProductionReportMetrics
GROUP BY MONTH(prm.EffectiveDate),
prm.NetRate_QuoteID
--this will be a check against the first joined table.
SELECT COUNT(*)
FROM NetRate_Quote_Insur_Quote Q
WHERE QuoteID IN
(SELECT NetRate_QuoteID
FROM ProductionReportMetrics
GROUP BY MONTH(prm.EffectiveDate),
prm.NetRate_QuoteID)
Basically you will want to do a similar check against each of your joined tables. If any of the joined tables are part of the grouping statement, make sure they are also in the grouping of the count check statement. Also make sure to alter the WHERE clause of the check count statement to use the join clause columns you were using.
Once you find a table that returns the incorrect number of rows, you will have your answer as to what table is causing the problem. Then you will just have to decide how to limit that table down to distinct rows(some type of aggregation).
This advice is really just to show you how to QA this particular query. Break it up into the smallest possible parts. In this case, we know that it is a join that is causing the problem, so take it one join at a time until you find the offender.
there is a column comment_id of a table called pic_alb_love which i'd like to add to the query below but i don't know how. Actually what i want to do is to count the total comment_id of the table pic_alb_love.
SELECT users_pics.wardrobe,
profile.fname,
users_pics.pic,
users_pics.u_pic_id,
users_pics.email,
users_pics.make,
users_pics.designer,
photo_comment.comment,
max_photo_comment.count_pic_id
FROM dbo.users_pics
INNER JOIN profile
ON users_pics.email = profile.email
LEFT Join (SELECT pic_id
,MAX(comment_id) max_comment_id
,COUNT(pic_id) count_pic_id
FROM photo_comment
GROUP BY pic_id
) max_photo_comment
On users_pics.u_pic_id = max_photo_comment.pic_id
LEFT Join photo_comment
On max_photo_comment.pic_id = photo_comment.pic_id
AND max_photo_comment.max_comment_id = photo_comment.comment_id
WHERE users_pics.wardrobe = MMColParam
AND users_pics.email = MMColParam2
ORDER BY u_pic_id asc
these are the various fields of the table pic_alb_love:
(comment_id,pic,love_com, wardrobe, email
,com_name,resp_email, play_count, com_stat)
LEFT JOIN (SELECT Pic
,Count(*) [CommentCount]
FROM pic_alb_love
GROUP BY Pic) c
ON c.Pic=u_pic_id
Assuming that pic_alb_love.pic is the FK on the table...
Use [CommentCount] in the select list.
Using SQL 2005: “Taking too much time to execute”
I want to filter the date, the date should not display in holidays, and I am using three tables with Inner Join
When I run the below query, It taking too much time to execute, because I filter the cardeventdate with three table.
Query
SELECT
PERSONID, CardEventDate tmp_cardevent3
WHERE (CardEventDate NOT IN
(SELECT T_CARDEVENT.CARDEVENTDATE
FROM T_PERSON
INNER JOIN T_CARDEVENT ON T_PERSON.PERSONID = T_CARDEVENT.PERSONID
INNER JOIN DUAL_PRO_II_TAS.dbo.T_WORKINOUTTIME ON T_CARDEVENT.CARDEVENTDAY = DUAL_PRO_II_TAS.dbo.T_WORKINOUTTIME.DAYCODE
AND T_PERSON.TACODE = DUAL_PRO_II_TAS.dbo.T_WORKINOUTTIME.TACODE
WHERE (DUAL_PRO_II_TAS.dbo.T_WORKINOUTTIME.HOLIDAY = 'true')
)
)
ORDER BY PERSONID, CardEventDate DESC
For the above mentioned Query, there is any other way to do date filter.
Expecting alternative queries for my query?
I'm pretty sure that it's not the joined tables that is the problem, but rather the "not in" that makes it slow.
Try to use a join instead:
select m.PERSONID, m.CardEventDate
from T_PERSON p
inner join T_CARDEVENT c on p.PERSONID = c.PERSONID
inner join DUAL_PRO_II_TAS.dbo.T_WORKINOUTTIME w
on c.CARDEVENTDAY = w.DAYCODE
and p.TACODE = w.TACODE
and w.HOLIDAY = 'true'
right join tmp_cardevent3 m on m.CardEventDate = c.CardEventDate
where c.CardEventDate is null
order by m.PERSONID, m.CardEventDate desc
(There is a from clause missing from your query, so I don't know what table you are trying to get the data from.)
Edit:
Put tmp_cardevent3 in the correct place.
Have you created indices on all of the columns that you are using to do the joins? In particular, I'd consider indices on PERSONID in T_CARDEVENT, TACODE in both T_PERSON and T_WORKINOUTTIME, and HOLIDAY in T_WORKINOUTTIME.