Re: LEFT joins

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Basile Francesco wrote:
In general, you should not worry about faster query sintax, since mysql should (but i'm not sure) have an "optimizer" inside wich translate your sintax query in a "better" efficient one.
Anyway, the "where" statement is perfectly equal to the "join" operator, it is called, in general, "theta-join" and in this case it is called "equi-join" (equi...because in the where statement you only compare attributes by the '=' operator).
The only reason you want to use the "left-join", which is a particular case for a general "outer-join", is if you want to fill your result with "NULL" values rather than an empty records.



cheers for that :-)

I remembered something along those lines but the specifics of JOINing always leak from my head. :-)

Jochem Maas ha scritto:
....

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