我怎样才能对变量进行排序？

Question

I don't know why it's not working... I'm trying to "order by" a created variable like this:

mysql_query("SELECT *,DATE_FORMAT(FROM_UNIXTIME(banfrom), '%d/%m/%Y') as time FROM ab_list WHERE time = '24/08/2013' ORDER BY banfrom DESC LIMIT 0,50");

Or,

   $hr = date('d/m/Y');
   mysql_query("SELECT *,DATE_FORMAT(FROM_UNIXTIME(banfrom), '%d/%m/%Y') as time FROM       ab_list WHERE time = '$hr' ORDER BY banfrom DESC LIMIT 0,50");

Answer 1

Assuming the variable $hr is in the format %d/%m/%Y, you can use having instead of where to filter the records.

mysql_query("SELECT *,DATE_FORMAT(FROM_UNIXTIME(banfrom), '%d/%m/%Y') as time 
             FROM ab_list 
             HAVING time = '$hr' 
             ORDER BY banfrom DESC 
             LIMIT 0,50");

The reason to use HAVING and not WHERE in this case is because time is computed column.