select
count(*)
from
TGraduateJob a,
TGraduateBaseInfo b,
TCollege d,
TCollege h,
TCode g
where
a.memberID = b.memberID and a.jobType in (0,2,7,1)
and (h.collegeID <> b.collegeID or h.ProvinceID != 7224)
and g.CodeID=b.WhereFrom
and g.CodeTypeID=13
and g.CodeValu like '35%'
--以上未经测试.
count(*)
from
TGraduateJob a,
TGraduateBaseInfo b,
TCollege d,
TCollege h,
TCode g
where
a.memberID = b.memberID and a.jobType in (0,2,7,1)
and (h.collegeID <> b.collegeID or h.ProvinceID != 7224)
and g.CodeID=b.WhereFrom
and g.CodeTypeID=13
and g.CodeValu like '35%'
--以上未经测试.
from TGraduateJob a,
TGraduateBaseInfo b,
TCollege d
where a.memberID = b.memberID
and a.memberID = d.memberID
and b.memberID = d.memberID
and a.jobType in (0,2,7,1)
and not exists
(
select 'X'
from TCollege h
where h.collegeID = b.collegeID
and h.ProvinceID = 7224
)
and exists
(
select 'X'
from TCode g
where g.CodeID=b.WhereFrom
and g.CodeTypeID=13
and g.CodeValu like '35%'
)
1、禁止关联查询,各自读入内存,且采用批量读出数据的方法,如:for MaxNum (祥见proc编程)
2、在内存中匹配关联条件
3、使用一些数据结构中的好的算法,如:平衡二叉树、折半查找、外部排序等。