ORACLE SQL查询仅重叠时间帧

Question

来自Emp表的数据：

NUM  DEPT   HIRED_SDT                       HIRED_EDT
---  -----  ------------------------------  ------------------------------
1    Sales  October, 01 2012 11:00:00+0000  October, 01 2012 11:30:00+0000
2    Sales  October, 01 2012 11:22:00+0000  October, 01 2012 12:40:00+0000
3    Sales  October, 01 2012 13:00:00+0000  October, 01 2012 13:50:00+0000
4    CC     October, 01 2012 14:00:00+0000  October, 01 2012 15:00:00+0000
5    CC     October, 01 2012 15:00:00+0000  October, 01 2012 16:10:00+0000
6    CC     October, 01 2012 16:00:00+0000  October, 01 2012 17:20:00+0000

期望的结果：

仅按部门分组的重叠时间范围

==＆GT;例如。在Sales内，有3个记录中有2个重叠

NUM  DEPT   HIRED_SDT                       HIRED_EDT
---  -----  ------------------------------  ------------------------------
1    Sales  October, 01 2012 11:00:00+0000  October, 01 2012 11:30:00+0000
2    Sales  October, 01 2012 11:22:00+0000  October, 01 2012 12:40:00+0000
5    CC     October, 01 2012 15:00:00+0000  October, 01 2012 16:10:00+0000
6    CC     October, 01 2012 16:00:00+0000  October, 01 2012 17:20:00+0000

http://sqlfiddle.com/#!4/91730/1

Answer 1

您可以尝试使用EXISTS：

SELECT *
FROM Emp e
WHERE EXISTS (
  SELECT *
  FROM Emp
  WHERE DEPT = e.DEPT
    AND HIRED_SDT < e.HIRED_EDT
    AND HIRED_EDT > e.HIRED_sDT
    AND NUM <> e.NUM
);

即。如果存在另一行属于同一个部门并且该行与该行重叠的行，则选择一行。