左外连接子查询答案

【问题标题】：Left Outer Join Subquery左外连接子查询
【发布时间】：2016-04-22 10:23:21
【问题描述】：

我正在尝试对子查询进行左外连接，这可能吗？

我可以这样做吗？：

##this is this weeks targets
select * from targets t
inner join streams s on s.id = t.stream_id
where t.week_no =WEEKOFYEAR(NOW())

left outer join

(
###############This is records selected so far this week
select p.brand_id, p.part_product_family, sum(r.best) from records r 
inner join products p on p.id = r.product_id
left outer join streams s on s.body = p.brand_id and s.stream = p.part_product_family
where WEEKOFYEAR(r.date_selected) =WEEKOFYEAR(NOW())
group by p.brand_id, p.part_product_family;
) sq_2

on s.stream = sq_2.part_product_family

【问题讨论】：

标签： mysql join left-join

【解决方案1】：

这是有效的：

    ##this is this weeks targets
select * from targets t
inner join streams s on s.id = t.stream_id

left outer join

(
###############This is records selected so far this week
select p.brand_id, p.part_product_family, sum(r.best) from records r 
inner join products p on p.id = r.product_id
left outer join streams s on s.body = p.brand_id and s.stream = p.part_product_family
where WEEKOFYEAR(r.date_selected) =WEEKOFYEAR(NOW()) and YEAR(r.date_selected) = YEAR(now())
group by p.brand_id, p.part_product_family
) sq_2

on s.body = sq_2.brand_id and s.stream = sq_2.part_product_family

【讨论】：