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Is there any difference?
Message
De
02/09/1997 19:26:00
 
 
À
02/09/1997 19:08:04
Information générale
Forum:
Visual FoxPro
Catégorie:
Codage, syntaxe et commandes
Divers
Thread ID:
00048114
Message ID:
00048153
Vues:
22
Jim, how can the SELECT know that a function included does not change its value (it is after all a function call) and though usually DATE() shouldn't change during the query (btw as Paul stated what happens if you run the query very close to midnight..) I don't think it is stupid to re-evaluate them Arnon >George, > >Pardon my English, but that would be awfully stupid of SQL - to run the >Date function for every record in the input. What makes you so sure it >would do so?? > >Enquiring minds need to know. > >regards, >Jim N > >>>Is there any optimization difference in the following: >>> >>>SELECT FIELD FROM TABLE WHERE FIELDDATE=DATE() INTO CURSOR TEMP >>> >>>OR >>> >>>ldDate=DATE() >>>SELECT FIELD FROM TABLE WHERE FIELDDATE=ldDate INTO CURSOR TEMP >> >>Michel, >> >>I'm not sure about differences in optimization, but the latter query >should execute faster. The reason being that the date function will have to >be called and it will have to return its value for every record in the >table. In the latter case, it simply a straight comparison. >> >>George >
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