如何查找此sql查询的行数？

$common_query_string = "Select a.INC_KEY,a.STATE, a.FDID, a.INC_DATE, a.INC_NO, a.EXP_NO, concat(a.NUM_MILE,' ', a.STREET_PRE,' ', a.STREETNAME,' ', a.STREETTYPE,' ',
          a.STREETSUF, ' ',a.APT_NO,' ', a.CITY,' ', a.STATE_ID,' ', a.ZIP5,' ', a.ZIP4) as address, a.latitude, a.longitude, 
          ( 3959 * acos( cos( radians($lat) ) * cos( radians( a.latitude ) )
          * cos( radians( a.longitude ) - radians($lon) ) 
          + sin( radians($lat) ) * sin( radians( a.latitude ) ) ) ) AS distance,
          a.INC_TYPE, a.FF_DEATH, a.OTH_DEATH, a.PROP_LOSS , a.CONT_LOSS,(b.CODE_DESCR) as INC_CODE_DESC, (d.CODE_DESCR) as CAUSE_CODE_DESC";


    $query = sprintf("$common_query_string ,'nfirs' as SOURCE
      From
        (Select * From incident
        Where latitude > '%s' And latitude < '%s' 
        And longitude > '%s' And longitude < '%s' %s) 
        As a , codelookup b,codelookup d
  Where a.INC_TYPE = b.code_value AND b.fieldid = 'INC_TYPE' 
  And  a.CAUSE_IGN  = d.code_value AND  d.fieldid = 'CAUSE_IGN'
      having distance < '%s'
       ", mysql_real_escape_string($minLat), mysql_real_escape_string($maxLat), mysql_real_escape_string($minLon), mysql_real_escape_string($maxLon), mysql_real_escape_string($query_condition), mysql_real_escape_string($radius));
$common_query_string = "Select a.INC_KEY,a.STAT