MySQL查询不从哪里条件中获取数据

Question

I have written a MySQL query ?I want to fetch data t.taskid = b.id OR t.taskid = '0' AND t.subtaskid = j.id OR t.subtaskid = '0' from this but where condition is not working for this

SELECT t.id as id
     , t.taskid
     , t.subtaskid
     , p.PNAME AS projectname
     , t.date AS DATE
     , b.Summary AS tasks
     , j.SUMMARY AS subtasks
     , t.mon AS time1
     , t.tue AS time2
     , t.wed AS time3
     , t.thu AS time4
     , t.fri AS time5
     , t.sat AS time6
     , t.sun AS time7  
  FROM bt_createissue b
     , bt_createissue j
     , timesheet t 
  LEFT
  JOIN bt_project p 
    ON t.projectid = p.pkey  
 WHERE t.taskid = b.id 
    OR t.taskid = 0 
   AND t.subtaskid = j.id  
    OR t.subtaskid = 0 
   AND t.date >= '2015-03-09' 
   AND t.date <= '2015-03-30' 
   AND t.username = '$username' 

Answer 1

If t.taskid = b.id t.subtaskid = j.id are to be joins then check whether you can modify

WHERE t.taskid = b.id OR t.taskid = '0' AND t.subtaskid = j.id OR t.subtaskid = '0'

the above lines with proper joins. Because using join conditions in where clause can create cross join instead of intended one.

If it do not work

Try with using having clause instead of where clause and don't forget to use group by