Re: Count the number of specific rows

[Philip Mather <philm@xxxxxxxxx>]

Servers24,
> Hi Philip,
>  
> Thank you very much for your help.
> Can you please tell me the differemce between COUNT(*) and COUNT(id) ?
> Thanks again.
Actually sorry I was a bit misleading there. MySQL is optimized to 
calculate...
   SELECT COUNT(*) FROM aTable;
...but given the fact you've got a where condition that optimizations 
probably no longer applicable, so I'd stick with...
   SELECT COUNT(id) FROM sent WHERE member_id = ...;
...the real difference would be when you do a SELECT COUNT(DISTINCT id) 
instead of a SELECT COUNT(DISTINCT *) which are different questions but 
not relevant to your situation.

Regards,
   Phil

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