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How to limit LEFT JOIN to one record only?
Message
 
 
To
07/02/2012 17:08:56
General information
Forum:
Visual FoxPro
Category:
Other
Environment versions
Visual FoxPro:
VFP 9 SP1
Miscellaneous
Thread ID:
01534771
Message ID:
01534780
Views:
41
>>Hi,
>>
>>I am trying to limit LEFT JOIN to select only one record. By design the child table should have only one record but I ran into a case where user had two records (wrong but it happens). And when two records are selected the entire resulting query is wrong. So, for example, say I have the following query:
>>
>>
>>select .... from Table1 left join Table2 on Table1.pk_field = Table2.pk_field
>>
>>
>>How can I change (if possible) the ON expression so that if Table2 has more than one record that matches the Table1.pk_field, only one is selected? (It does not matter to me which one). TIA.
>
>First of all, are you using VFP or SQL Server for this query? Secondly, do you want one record per each ID or you're selecting only for the particular ID (in this case Sergey's solution will work). For the 1 record per ID there is no good and simple VFP based solution available.

I am trying to make this syntax work for either VFP or SQL Server. To answer the second part of your question, I want ONE RECORD PER EACH ID. If there is not solution, I will have to do more checking (before running this query) to be sure that the child table has only one record for the unique ID.
Thank you.
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