加入两个多对多关系，'all'operator

我有四个值表：教师，认证，block_subjects和块以及两个关系表：instructor_certifications和subject_certification。就像这样：加入两个多对多关系，'all'operator

block -- block_subject 
      | 
      | 
subject_certification 
      | 
      | 
    certification 
      | 
      | 
instructor_certification 
      | 
      | 
     instructor

我想要一个查询，会告诉我，每个块，其中教官师资块。具体来说，我不想指定块ID作为查询的一部分;我想根据不同的标准选择多个块。

这里是（非工作）查询我目前有：

select inst.name, inst.id 
from instructor as inst 
join instructor_certification as ic on inst.id = ic.instructor_fid and 
ic.certification_fid = all (
    select cert.id 
    from block_subject as bs 
    join subject_certification as bsc on bsc.block_fid = bs.id 
    join certification as cert on bsc.certification_fid = cert.id 
    where bs.id = any (
     select bs.id 
    from block as b 
     join block_subject as bs on b.subject_fid = bs.id 
     where (b.start_date, b.end_date) overlaps (?, ?) 
    ) 
)

显然，这并不工作，因为“所有”收集所有在日期范围内的所有block_subject所需的认证。

编辑：另外我应该澄清，实际上，每个block_subject需要多个认证。

来源

2011-05-20 gibbss

听起来像你对我要求的关系运算符是[师]（http://www.simple-talk.com/sql/t-sql-编程/划分我们的关系SQL的分支/）：“提供所有部分的供应商” - >“可以教授块上所有主题的教师”，或许？ – onedaywhen 2011-05-20 06:09:04

这看起来像我需要的......哦，从来没有真正采取数据库类的乐趣。 – gibbss 2011-05-20 06:51:47

好的，我将其更改为新的要求。 – Hogan 2011-05-20 10:15:09

编辑后：

如果要求每块每名教师多证书：

select b.id as blockid, bs.subject_id as subject_id, i.id as inscructorid, count(ic.certification_id) as numCerts 
from block b 
join block_subject bs on b.id = bs.block_id 
join subject_certification sc on bs.subject_id = sc.subject_id 
join instructor_certification ic on sc.certification_id = ic.certification_id 
join instructor i on ic.instructor_id = i.id 
group by b.id, bs.subject_id, i.id 
having count(ic.certification_id) > 1

您的问题，指出 “每块”。所以，从块开始，然后做连接。像这样：

select * 
from block b 
join block_subject bs on b.id = bs.block_id 
join subject_certification sc on bs.subject_id = sc.subject_id 
join instructor_certification ic on sc.certification_id = ic.certification_id 
join instructor i on ic.instructor_id = i.id

您现在可以添加任何您想要的标准。

特定块？

日期范围？

where @Date between b.start_date and b.end_date

指导员？

where i.id = @inid

认证？或者其组合。

来源

2011-05-20 03:07:00 Hogan

给这个镜头。

declare @Date datetime 

set @Date = '01/01/2011' 

select inst.name, inst.id 
from instructor as inst 
join instructor_certification as ic on inst.id = ic.instructor_fid 
and ic.certification_fid in (
    select cert.id 
    from block_subject as bs 
    join subject_certification as bsc on bsc.block_fid = bs.id 
    join certification as cert on bsc.certification_fid = cert.id 
    where bs.id in (select bs.id 
     from block as b 
     join block_subject as bs on b.subject_fid = bs.id 
     where @Date between b.start_date and b.end_date)) 
    ) x

来源

2011-05-20 03:07:40 Vinnie

只是教官......

select 
    i.* 
from 
    instructor i on 
where 
    exists (
    select * 
    from 
     block b 
     join block_subject bs on b.id = bs.block_id 
     join subject_certification sc on bs.subject_id = sc.subject_id 
     join instructor_certification ic on sc.certification_id = ic.certification_id 
     WHERE 
     ic.instructor_id = i.id 
     AND 
     ..other filters here 
     )

来源

2011-05-20 05:02:50 gbn

加入两个多对多关系，'all'operator

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