Plateforme Level Extreme
Abonnement
Profil corporatif
Produits & Services
Support
Légal
English
Another weird issue with ANSI SQL
Message
 
 
À
08/02/2003 00:16:18
Information générale
Forum:
Visual FoxPro
Catégorie:
Base de données, Tables, Vues, Index et syntaxe SQL
Divers
Thread ID:
00750934
Message ID:
00750944
Vues:
30
>>VFP8 doesn't allow memo or general field in UNION. Would UNION ALL work for you in this case? It doesn't have such restriction.
>
>When I assumed that, I change it to use the same approach as the GROUP BY. So, I only extract the IDs first and then do another SQL to get the rest.

That would work too. I guess, I wasn't clear in my previous message. You could change UNION to UNION ALL and it would work. UNION should be only used in the queries that could produce duplicate records, to eliminate those duplicates. UNION ALL is also faster because it doesn't do anything with result set. UNION, on other hand, does DISTINCT on the result set. That's where VFP generates an error on memo fields because it doesn't compare them for performance reason.
--sb--
Précédent
Suivant
Répondre
Fil
Voir

Click here to load this message in the networking platform