优化前：
|
1
2
|
select
b.type, ifnull(
count
(0),0)
as
qty
from
b_sell_quotationd a,b_sell_quotation b
where
b.quotationNo=a.quotationNo
and
a.status=
'N'
and
b.companycode=
'XXXXX'
AND
b.type=
'general'
;
|
优化后：
select COUNT(0) from b_sell_quotationd a LEFT JOIN (SELECT * FROM b_sell_quotation WHERE type='general') b ON b.quotationNo=a.quotationNo WHERE b.companycode='XXXXXX' and a.status='N'
本文转自yunlielai51CTO博客，原文链接：http://blog.51cto.com/4925054/1883231，如需转载请自行联系原作者
