Group By "" Order By "" confusion

Rodney_H_

How come THIS query yields 11 results:

$query = "SELECT resource_categories.category, resources.id, resources.cid, resources.name, resources.description  

		  FROM `resource_categories`, `resources`
		  WHERE  resource_categories.id = resources.cid
		  ORDER BY resources.cid";

And THIS query yields only 8 results:

$query = "SELECT resource_categories.category, resources.id, resources.cid, resources.name, resources.description  

		  FROM `resource_categories`, `resources`
		  WHERE  resource_categories.id = resources.cid
		  GROUP BY resources.cid
		  ORDER BY resources.timestamp";

Basically I wanted to group all the resources in the same categories together...

Thanks for your help and for pointing out, what will likely be the obvious, to me...

bogu

Because u dont know what GROUP BY do ...
U should check this link: http://dev.mysql.com/doc/refman/4.1/en/group-by-hidden-fields.html