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Selecting the first one from a group
Message
De
29/02/2000 13:07:47
 
 
À
29/02/2000 12:53:19
Information générale
Forum:
Visual FoxPro
Catégorie:
Base de données, Tables, Vues, Index et syntaxe SQL
Divers
Thread ID:
00338912
Message ID:
00339270
Vues:
23
>>>>If so, this combination should do it (note slight change in first SQL)
SELECT MIN(PrimaryKey) AS pk, SecondaryKey AS sk ;
>>>>FROM Table INTO CURSOR TEMP ;
>>>>GROUP BY 2
>>>>* now choose smaller of two for first column
>>>>SELECT EVAL("MIN(pk,sk)") AS pk, sk FROM temp
>>>
>>>Thanks to all who helped me on this.
>>>
>>>I chose this approach. I guess all approaches sent are good as well. And, the speed is good as well.
>>
>>As usual, the Fox gives us *many* ways to solve a problem.
>
>And here's one more. The non-SQL approach:
>
>INDEX ON SecondaryKey TO whatever UNIQUE
>COPY FIELDS PrimaryKey,SecondaryKey TO whatever

But that would not always give the *lowest* PrimaryKey for each SecondaryKey, which was part of the requirement.
David Stevenson, MCSD, 2-time VFP MVP / St. Petersburg, FL USA / david@topstrategies.com
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