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Correlated subquery
Message
De
19/03/2021 07:54:46
 
 
À
18/03/2021 15:49:55
Lutz Scheffler
Lutz Scheffler Software Ingenieurbüro
Dresden, Allemagne
Information générale
Forum:
Visual FoxPro
Catégorie:
Base de données, Tables, Vues, Index et syntaxe SQL
Divers
Thread ID:
01679045
Message ID:
01679110
Vues:
57
>I can express
>
>select * from MyTable   outside  
>    where exists   
>          ( select 1 from DiscountMaster inside where inside.active = 'N')
>
>
>??
>EXIST () is just EMPTY SET or NOT EMPTY SET. There is nothing said about correlation.
>

OK, point taken, so I'll paraphrase...I'm hard-pressed to think of any practical example where the subquery with an EXISTS will not be correlated. Correct, you can do that and it will execute, but beyond that, not sure anyone would write that :)
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