Mysql returns only one row when using Count

Question

Well I\'ve just hit a weird behaviour that I\'ve never seen before, or haven\'t noticed.

I\'m using this query:

  SELECT *, 
         COUNT(*) AS pag         


        

Answer 1

Using an aggregate function without a GROUP BY will always return one row, no matter what. You must use a GROUP BY if you want to return more than one row.

Note that on most RDBMS, such a query would have failed because it makes no sense.