mysql - Select values with latest date and group by an other column -

Myquery is getting the exact results I need, but when the data exceeds more than 1000 rows Select it Skilled

  Select ID, `UID`, Case Left_Leg & gt; If right_f then left_leg and left_leg and max_leg, select `date` from` date` (SELECT * FROM network t2 where id (choose ID (choose ID, uid, `date` (select from network order by 'UID', 'date' Descend) by TIDE group by UID) T3 and (left_log> = 500 or right_AGEGGDAG> = 500)) T1   
 To get data from the network, want the latest dates for each UID Are & Gt; = 500 or right_legue & gt; = 500 wanted to take only two legs (left or right)  
 Maybe there may be some questions but  core problem  is with this code  
  SELECT * from network t2 where id (select id by UID, UID, `date`) (select * UID by network order, 'date' given t4 group) T3)   
  I want to improve this query because the data has increased so much that when the data increases. First of all, get the maximum date for each UID  
 Search Associate ID      
 Filter on the values ​​of the feet   
 Example:  
  SELECT id, UID, Greatest (left_geal, right_lag) as the Max_leg network from WHERE (UID, `date`) (selection by UID, Max (` date`) from the network group by UID) and (left_log> 500 or right_lag> 500)   
 Meditation Let that mean that if uid Area for a foot in the latest date & gt; 500, then results will not show up in the record. If you want the latest record with feet & gt; 500, the foot filter has to be taken in.