寻找有关将多个SQL查询组合成一个多部分内部连接语句的建议。
我有以下三个表(表:列(:
-
访问表:pid、visit_date、visit_start_datetime、visit_end_datetime、visit_id、visit_type、visit_length、visit_rating
-
电汇表:pid、cond_date、cond_datetime、cond_id、cond_type、cond_length、cond_rating
-
产品表:pid、prod_id、prod_date、prod_start_datetime、prod_end_datetime、prod_rating、prod_price
我有以下原子SQL查询:
select pid, visit_date, visit_start_datetime, visit_end_datetime
from VisitTable
where visit_id = XYZ AND visit_start_datetime > '01/01/2009'
select pid, cond_date, cond_datetime
from CondTable
where cond_id in (ABC, DEF, GHI)
select pid, prod_date, prod_start_datetime, prod_end_datetime
from ProdTable
where prod_id in (123, 456, 789)
让我们调用第一个查询 (Temp1
(、第二个查询 (Temp2
( 和第三个查询 (Temp3
( 的结果。
我想在pid
where (Temp1.visit_start_datetime <= Temp2.cond_datetime <= Temp1.visit_end_datetime
( 上将Temp1
与Temp2
进行内部连接,即在该pid
的范围内Temp2.cond_datetime
在范围内[Temp1.visit_start_datetime, Temp1.visit_end_datetime]
的情况下。我们将此连接的结果称为Temp4
。
然后我想把这个结果(Temp4
(与Temp3
在Temp3.prod_start_datetime
在范围内[Temp1.visit_start_datetime, Temp1.visit_end_datetime]
的pid
内连接。
问题:
- 如何使用具有多个内部联接和条件的 1 个 SQL 查询来执行此操作?
我尝试了以下语法,但不正确:
select pid, visit_date, visit_start_datetime, visit_end_datetime
from VisitTable
where visit_id = XYZ AND visit_start_datetime > '01/01/2009'
left join
(select pid, cond_date, cond_datetime
from CondTable
where cond_id in (ABC, DEF, GHI)) Temp2 on Temp2.pid = VisitTable.pid
where Temp2.cond_datetime between VisitTable.visit_start_datetime and VisitTable.visit_end_datetime
left join
(select pid, prod_date, prod_start_datetime, prod_end_datetime
from ProdTable
where prod_id in (123, 456, 789)) Temp3 on Temp3.pid = VisitTable.pid
where Temp3.prod_start_datetime between VisitTable.visit_start_datetime and VisitTable.visit_end_datetime
在第一个原子SQL查询中,我最初尝试使用带有
visit_date
的WHERE
子句,但收到错误消息,说"visit_date"是整数。然后我尝试使用visit_start_datetime
,它接受了条件>= '01/01/2009'
。为什么会发生这种情况,无论如何我可以使用visit_date
吗?构造此查询后,如何按日期分组并计算每个日期显示的条目数?
谢谢!
请尝试以下 SQL,您的日期格式未被 SQL 查询理解。
select Temp1.* from
(
select pid, visit_date, visit_start_datetime, visit_end_datetime
from VisitTable
where visit_id = XYZ AND visit_start_datetime > '2009-01-01'
) as Temp1 inner join
(
select pid, cond_date, cond_datetime
from CondTable
where cond_id in (ABC, DEF, GHI)
) as Temp2 on Temp1.pid = Temp2.pid
and Temp1.visit_start_datetime <= Temp2.cond_datetime and Temp2.cond_datetime <= Temp1.visit_end_datetime
inner join
(
select pid, prod_date, prod_start_datetime, prod_end_datetime
from ProdTable
where prod_id in (123, 456, 789)
) as Temp3 on Temp1.pid = Temp3.pid
and Temp1.visit_start_datetime <= Temp3.prod_start_datetime and Temp3.prod_start_datetime <= Temp1.visit_end_datetime