Re: query - select from one, update another

[Jasper Bryant-Greene]

Michael Stassen wrote:
> 
> Not exactly.  They aren't the same.  COUNT(id) counts distinct values of 
> id, while COUNT(*) simply counts rows.  [snip]

Actually, COUNT(id) counts non-NULL values of id. COUNT(DISTINCT id) 
would count distinct values.

http://dev.mysql.com/doc/mysql/en/group-by-functions.html#id2873509

Jasper