将表格与自身进行比较

我试图将同一张表格与其自身进行比较，以将一个员工位置与另一位表格进行比较。我希望能够选择一名员工是否只来自另一名员工的某个地点。将表格与自身进行比较

表看起来像这样

StaffNo LocoNo 
1   1 
1   2 
1   3 
3   2 
3   3 
3   4 
4   1 
4   2 
5   2 
5   3 
6   1 
6   2

说比较职员1和4

结果将

StaffNo LocoNo 
1   3

我已经试过内部联接和EXCEPT，但现在看来似乎不起作用。

来源

2012-10-05 Michael Rowley

什么样的SQL的？ – podiluska

你想要“第一个StaffNo在场的地方，但第二个不在”或“只有以下两名员工中的一个在场的地点”？即搜索是否意味着对你给出的两个职员编号的顺序无动于衷？ –

SELECT StaffNo 
    , LocoNo 
    FROM Tbl A 
WHERE NOT EXISTS 
     (SELECT 1 
     FROM Tbl B 
     WHERE A.StaffNo <> B.StaffNo 
      AND A.LocoNo = B.LocoNo)

来源

2012-10-06 16:16:10

我用你的例子，并使用它一点点，以使其工作。这是我终于从你的例子中完成的工作。 SELECT StaffNo，LocoNo FROM TBL甲 WHERE A.StaffNo = 1 AND NOT EXISTS （SELECT 1 FROM TBL乙 WHERE B.StaffNo = 4 AND A.LocoNo = B.LocoNo） –

内部联接只在联接的两端匹配时才返回结果。当你在寻找差异时，你需要一个外部联接。喜欢这个。

select 
    COALESCE(t1.staffid, t2.staffid) as staff, 
    COALESCE(t1.locationid, t2.locationid) as location 
from 
    (select * from table where staffid=1) t1 
     full outer join 
    (select * from table where staffid=4) t2  
     on t1.locationid = t2.locationid 
where t1.locationid is null 
or t2.locationid is null

来源

2012-10-05 13:43:19 podiluska

select staffno,locono from tbl where staffno in (1,4) and locono in 
((select locono from tbl where staffno = 1 
except 
select locono from tbl where staffno = 4) 
union 
(select locono from tbl where staffno = 4 
except 
select locono from tbl where staffno = 1))

来源

2012-10-05 13:51:11 Seasoned

另一种解决方案使用减号/ UNION ALL：

with 
    v_1 as (select locono from from table where staffid=1), 
    v_2 as (select locono from from table where staffid=2) 
select * from (
(select 1 staffid, locono from v_1 
minus 
select 1 staffid, locono from v_2 
) 
union all 
(
select 2 staffid, locono from v_2 
minus 
select 2 staffid, locono from v_1 
)) order by staffid, locono

来源

2012-10-05 13:52:41

将表格与自身进行比较

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