看的有点糊涂的增删改的sql语句

--不存在的记录删掉
  delete a from ECOrganizationPositionRelation a left join @ECOrganizationPositionRelation b
  on a.OrganPostionID=b.OrganizationID and a.PositionID=b.PositionID
  where not exists(select * from ECOrganizationPositionRelation where OrganizationID=b.OrganizationID and PositionID=b.PositionID)
  --存在的记录修改
  update a set
  OrganizationID=b.OrganizationID,
  PositionID=b.PositionID
  from ECOrganizationPositionRelation a,@ECOrganizationPositionRelation b
  where a.OrganizationID=b.OrganizationID and a.PositionID=b.PositionID
  --没有的记录增加
  insert into dbo.ECOrganizationPositionRelation(OrganPostionID,OrganizationID,PositionID)
  select
        NEWID(),
        OrganizationID,
        PositionID
        from @ECOrganizationPositionRelation b
        where  not exists(
    select * from ECOrganizationPositionRelation
     where OrganizationID=b.OrganizationID and PositionID=b.PositionID
    )