选择一列中相同但在另一列中不同的行

Question

X    Y    DATE
1    20   20120101
1    21   20120101
2    30   20120201
3    40   20120201
3    41   20120301

我想选择任何行，其中X是相同的另一行，但日期不同，即答案是

3    40   20120201
3    41   20120301

Answer 1

试试这个......

SELECT *
FROM YourTable
WHERE X IN (
  SELECT T1.X
  FROM YourTable T1 INNER JOIN
       YourTable T2 ON T1.X = T2.X
  WHERE T1.DATE <> T2.DATE
);

这应该适用于大多数符合ANSI标准的数据库产品。

Answer 2

select distinct t1.*
  from table t1
  join table t2
    on (t1.X = t2.X and t1.date <> t2.date);

Answer 3

declare @t table(X int, Y int, DATE CHAR(8))
insert @t values
(1, 20, '20120101' ),
(1, 21, '20120101' ),
(2, 30, '20120201'),
(3, 40, '20120201'),
(3, 41, '20120301')

select x,y, date, maxy, miny from
(
  select *, max(date) over (partition by x) maxdate, 
  min(date) over (partition by x) mindate
  from @t
) a
where mindate <> maxdate