Question

以下表格是我遇到的问题的一个例子：

公司 {Id}

公司人员 {CompanyId，PeopleId}

人 {Id}

PeopleChildren {PeopleId，ChildrenId}

儿童 {Id}

我想删除公司的所有人，然后删除人员的子女。

我不能删除人员而不删除联接表 CompanyPeople 中的项目。但是，如果我这样做，我找不到哪些人是公司的一部分。

同样的问题紧跟儿童

最好的方法是什么？

Answer 1

我通常会使用table variables或temp tables来捕获首先使用的数据，然后执行删除操作：

declare @people table (PersonID int not null)
create table #children (ChildrenID int not null)

insert into @people(PersonID)
select PersonID from CompanyPeople
where CompanyID = @CompanyToRemove
insert into #children (ChildrenID)
select ChildrenID from PeopleChildren
where PersonID in (select PersonID from @people)

delete from PeopleChildren where PersonID in (select PersonID from @people)
delete from Children where ChildrenID in (select ChildrenID from #children)
delete from CompanyPeople where PersonID in (select PersonID from @people)
delete from People where PersonID in (select PersonID from @people)

Answer 2

您可以通过

删除首先要删除公司的人员的子女

delete from Children where ChildrenID in (select ChildrenID from Children, PeopleChildren, CompanyPeople where Children.ChildrenID = PeopleChildren.ChildrenID and PeopleChildren.PeopleID = CompanyPeople.PeopleID and CompanyPeople.CompanyID = ?)

然后只有您通过

删除人员

delete from People where PeopleID in (select PeopleID from CompanyPeople where CompanyPeople.CompanyID = ?)

Answer 3

我想我会使用输出子句，我认为这会很快因为没有插入而且少了几个sql语句

这不完整

declare @people table (PersonID int not null)
 DELETE FROM PeopleChildren
FROM  @people p INNER JOIN
 PeopleChildren pc  ON p.ID = pc.ID
 output deleted.id into @people

 delete from People p 
 from People inner join  @people p1 on p.PersonID=p1. PersonID

删除关系连接表

3 个答案: