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LEFT JOIN vs FULL JOIN
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Information générale
Forum:
Visual FoxPro
Catégorie:
Base de données, Tables, Vues, Index et syntaxe SQL
Versions des environnements
Visual FoxPro:
VFP 9 SP1
Divers
Thread ID:
01514564
Message ID:
01514598
Vues:
72
>Hi,
>
>I am working on joining two tables into a query and it looks like Selecting From Table1 and FULL JOIN Table2 is the same as Select from Table2 and LEFT JOINT Table1. Is there advantage using one or the other? The tables/queries Table1 and Table2 are very small (less than 100 records) so I am not sure there would be difference in speed. But I am wondering if one is more practical then the other. TIA.

The results returtned by LEFT JOIN vs. FULL JOIN are different when you have non-matching records in both tables. If you only have, say, records in Table1 and some of them don't have matching records in Table2, but the opposite is not true, then LEFT JOIN and FULL JOIN will return the exactly same result and if you can anticipate this situation, it's better to use LEFT JOIN then.
If it's not broken, fix it until it is.


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