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Need help writing an SQL statement that has specific count in WHERE clause

Posted on 2009-07-01
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Last Modified: 2012-05-07
Greetings i am having trouble getting this to work...
What i need is to return the results from tbl_A where when joined to tbl_B the information is NOT duplicated 6 times.

Basically here is my problem. i have an items location table (tbl_B) with fields like UID (Primary Key), CID (category ID), InternalID (item Id), Priority (order of Items)....

Lets say i  have 6 items in the category with a CID of '564' when i write an SQL table Join with no WHERE statement i get 6 results just for that CID, which in turn tells me there are 6 items in that category. What i need to find is the categories without 6 items in them. Apparently the client wants only 6 items in each category. no more no less... Is it possible to get an SQL statement to find only those categories? Hope this make sense, and thanks in advance for any help!
SELECT * FROM tbl_A 
    LEFT JOIN tbl_B ON tbl_B.CID = A.CID 
 
Need to write WHERE duplicates != 6

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Question by:Fullsource
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6 Comments
 
LVL 4

Assisted Solution

by:j_s_kelley
j_s_kelley earned 400 total points
ID: 24755173
Try this to get you started.  Haven't checked syntax but this is close to what you want I think.
SELECT tbl_B.CID FROM tbl_A 
    LEFT JOIN tbl_B ON tbl_B.CID = A.CID
Group by tbl_B.CID
Having Count(tbl_B.CID) <> 6

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LVL 75

Assisted Solution

by:Aneesh Retnakaran
Aneesh Retnakaran earned 400 total points
ID: 24755181
Hello Fullsource,

SELECT *
FROM tbl_A
WHERE CID NOT IN (SELECT CID FROM tbl_B GROUP BY CID HAVING COUNT(*) = 6 )

Regards,

Aneesh
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LVL 23

Expert Comment

by:Racim BOUDJAKDJI
ID: 24755293
I'd suggest...

select distinct A.CID
from tbl_A  A
        inner join tbl_B B
        on A.CID = B.CID
group by A.CID
having count(distinct B.UID) < = 6
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LVL 23

Accepted Solution

by:
Racim BOUDJAKDJI earned 1200 total points
ID: 24755337
select distinct A.*
from tbl_A A
inner join
(
select distinct CID from tbl_B group by CID
having count(distinct UID) < = 6
) B
on A.CID = B.CID
0
 
LVL 4

Expert Comment

by:j_s_kelley
ID: 24755518
Be careful.  Racimo's answer has a less than or equal.  This is not what you stated.  You wanted answers that were not exactly 6.  His answer will give you CID's that have 6 rows in B, or 5 rows, or 4 rows, etc....

Also, be careful using a Not In clause because it is very inefficient.  I don't care about the points so much, you just need to know that the accepted solution doesn't answer the question as stated.  I also am not trying to be difficult but my nature is to be as complete as possible.
0
 
LVL 23

Expert Comment

by:Racim BOUDJAKDJI
ID: 24755664
<<Be careful.  Racimo's answer has a less than or equal.  This is not what you stated.  You wanted answers that were not exactly 6.  His answer will give you CID's that have 6 rows in B, or 5 rows, or 4 rows, etc....>>
Not totlly clear I realize by your comment...but the questionner also specified *Apparently the client wants only 6 items in each category. no more no less* which is why I considered that any value below or equal 6 is necessary.  In that case, the query provided *does* answer the question.  

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