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MySQL query limit records in only one table on inner join

Posted on 2011-03-12
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Last Modified: 2012-05-11
Hi,

Not sure that the title really describes what I am doing here but basically as follows,

Query selecting prodHead (basic product details such as prod code and description)
Joining prodSku (multiple records per prodHead to allow for variants such as colours, size, price)
prodMenuIndex (ndex of prodHead records in the current menu section being viewed.

As the prodSku has multiple option I just want to limit the selection to 1 (the cheapest based on prodsku.net) but as you will see from the attached query it will bring back all associated prodSku records.

Any help appreciated

Cheers
SELECT 
        prodMenuIndex.*,
        prodHead.prodCode,
        prodHead.prodDesc,
        prodSku.prodId,
        prodSku.free,
        prodSku.net 
        FROM prodMenuIndex 
        INNER JOIN prodHead 
        ON prodMenuIndex.prodCode = prodHead.prodCode 
        INNER JOIN prodSku 
        ON prodHead.prodCode = prodSku.prodCode
        WHERE prodMenuIndex.menuId = #currentMenu#
        AND ProdHead.Avail = 1 
        AND prodSku.Avail = 1
        ORDER BY #sortOrder# 
        <cfif IsDefined("url.StartRow") and IsDefined("ResultsPerPage")>
		LIMIT #url.StartRow#, #ResultsPerPage#
        </cfif>

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Question by:Lmillard
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4 Comments
 
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Expert Comment

by:cyrusjoudieh
ID: 35116264
Here is a sample how to limit the query by one result.

Assuming :
prodSku Many to 1 in relation to prodHead
prodSku is Many to 1 in relation to prodMenuIndex

SELECT  prodSku.prodCode,
        prodHead.prodCode,
        prodHead.prodDesc,
        prodMenuIndex.*,
        prodSku.prodId,
        prodSku.free,
        prodSku.net
        FROM prodSku
        INNER JOIN prodHead ON prodHead.prodCode = prodSku.prodCode
        INNER JOIN prodMenuIndex ON prodMenuIndex.prodCode = prodHead.prodCode
        WHERE prodHead.Avail = 1 AND prodSku.Avail = 1
ORDER BY prodSku.net ASC LIMIT 1

If you can provide a sample data tables it would be a lot faster.

Mysql.txt
0
 

Author Comment

by:Lmillard
ID: 35116418
Hi,
The sample only brings back one record in all, the issue I have is that I want to return all records but if a prodHead record has 3 prodSku records linked I want only the cheapest prodSku record to be retrieved so if I have 3 prodhead records, 3 prodmenu records and 10 prodsku records, the query will always return 3 records as the prodsku link is limited to one but not the entire query

Sorry for not providing data samples but the tables have loads of fields so I was hoping this was an easy one that someone would just know off the top of their head.
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LVL 2

Accepted Solution

by:
cyrusjoudieh earned 500 total points
ID: 35116483
Ok, then you need to group by prodCode then
0
 

Author Closing Comment

by:Lmillard
ID: 35116559
Of course! Thanks for that, long day and cant see the wood for the trees!
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