在MySQL中结合2个选择查询

Question

I have 2 select statements:

1. timestamp of emp getting awards for specific emp id

   SELECT * FROM user_table,employeetable,awards where user_table.empid=employeetable.empid AND user_table.empid=awards.empid AND user_table.empid=123 ORDER BY timestamp DESC

2. All employees staying around 25 miles from the current loc: current location: lat =37 lng=-122

   SELECT * ( 3959 * acos( cos( radians(37) ) * cos( radians( lat ) ) * cos( radians( lng ) - radians(-122) )+ sin( radians(37) ) * sin( radians( lat ) ) ) ) AS distance FROM user_table,employeetable,awards where user_table.empid=employeetable.empid AND user_table.empid=awards.empid HAVING distance < 25 ORDER BY distance;

How do I combine both and ORDER BY timestamp ?btw both have field timestamp.

1.has specific user
2.all users within specific radius

I really appreciate any help.Thanks in Advance.

Answer 1

You can combine the two queries into a single query, just using logic in the where clause (which this has turned into a having clause:

select *, ( 3959 * acos( cos( radians(37) ) * cos( radians( lat ) ) * cos( radians( lng ) - radians(-122) )+ sin( radians(37) ) * sin( radians( lat ) ) ) ) as distance
from user u join
     employee e
     on u.empid = e.empid join
     awards a
     on u.empid = a.empid
having empid = 123 or distance < 25;

This uses having instead of where so the distance column alias can be used instead of the formula.