The following is an sql statement that I use mysql to calculate distance. This sql is too complex. I want to simplify it by using mysql stored procedures or stored functions
$select = 't.*,(ACOS(SIN((' . $this->latitude . '* 3.1415) / 180 )
*SIN((travel_user_status.latitude * 3.1415) / 180 )
Plus cos (('.$ this-> latitude.' * 3.1415)/180) *
COS((travel_user_status.latitude * 3.1415) / 180 ) *
COS((' . $this->longitude . '* 3.1415) / 180 -
(travel_user_status.longitude * 3.1415)/180 )) * 6378.137)
as distance';
$join = 'LEFT JOIN travel_user_status ON travel_user_status.userId=t.userId';
Finally want to become like this:
$select = 't.*,distance($this->latitude,$this->longitude) as distance';
$join = 'LEFT JOIN travel_user_status ON travel_user_status.userId=t.userId';
This distance is like a mysql function that can be called directly
What should I do? ?
Look up the manual by yourself:http://dev.mysql.com/doc/refman/5.0/en/create-function-udf.html