以下查询挂起:(尽管子查询单独执行很好)为什么我的MySQL查询使用子选择挂起?
我不知道如何使解释表看起来没问题。如果有人告诉我,我会清理它。
select
sum(grades.points)) as p,
from assignments
left join grades using (assignmentID)
where gradeID IN
(select grades.gradeID
from assignments
left join grades using (assignmentID)
where ... grades.date <= '1255503600' AND grades.date >= '984902400'
group by assignmentID order by grades.date DESC);
我认为问题是与第一年级的表...类型ALL与许多行似乎是原因..一切都索引。
我上传了表格作为图像。无法得到正确的格式: http://imgur.com/AjX34.png
一个评论者想全where子句:
explain extended select count(assignments.assignmentID) as asscount, sum(TRIM(TRAILING '-' FROM grades.points)) as p, sum(assignments.points) as t
from assignments left join grades using (assignmentID)
where gradeID IN
(select grades.gradeID from assignments left join grades using (assignmentID) left join as_types on as_types.ID = assignments.type
where assignments.classID = '7815'
and (assignments.type = 30170)
and grades.contactID = 7141
and grades.points REGEXP '^[-]?[0-9]+[-]?'
and grades.points != '-'
and grades.points != ''
and (grades.pointsposs IS NULL or grades.pointsposs = '')
and grades.date <= '1255503600'
AND grades.date >= '984902400'
group by assignmentID
order by grades.date DESC);
有问题吗? – jjclarkson 2009-10-21 16:21:47
请使用语法hilighting和结构的代码,我不能读取这个:( – 2009-10-21 16:25:47
我修复了查询,但我不知道如何让表格格式。我需要使用html表格标签? – Stephane 2009-10-21 16:33:43