Oracle SQL将多行聚合为单行

我有一个表格，每个PUNCHDTM格式存储员工打孔的1行。该表有一个SHIFTID来关联属于其班次的所有穿孔，我想要一种方法来获得其自己列中的所有单个穿孔，每个SHIFTID给我一行。我无法确定有多少拳（有些有2拳，有些有10，12°），这让我觉得一些动态的东西会很难。如果不可能动态地获得所有的冲头，那么仅仅抓住前6个冲头就足够了

这是一个示例数据集（我用密集的_秩对每班的打孔次数进行了排序）

员工ID SHIFTID SHIFTDATE PUNCHTM等级
0000016431140051010/16/2017 10/16/2017 03:29下午1点
0000016431140051010/16/2017 10/16/2017 08:02下午2点
0000016431140051010/16/2017 10/16/2017 08:32下午3点
0000016431140051010/16/2017 10/16/2017 10:30下午4点
0000016431140458110/17/2017 10/17/2017 02:57下午1点
0000016431140458110/17/2017 10/17/2017 07:20下午2点

正如您所说，很难动态执行此操作，因为它需要硬编码。但你肯定可以打6拳：

select EMPLOYEEID
    , SHIFTID
    , SHIFTDATE
    , max(case when rank = 1 then PUNCHDTM else null end)  as PUNCHDTM1
    , max(case when rank = 2 then PUNCHDTM else null end)  as PUNCHDTM2
    , max(case when rank = 3 then PUNCHDTM else null end)  as PUNCHDTM3
    , max(case when rank = 4 then PUNCHDTM else null end)  as PUNCHDTM4
    , max(case when rank = 5 then PUNCHDTM else null end)  as PUNCHDTM5
    , max(case when rank = 6 then PUNCHDTM else null end)  as PUNCHDTM6
from employees
group by 1,2,3

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就像你说的，动态地做这件事很难，因为它需要硬编码。但你肯定可以打6拳：

select EMPLOYEEID
    , SHIFTID
    , SHIFTDATE
    , max(case when rank = 1 then PUNCHDTM else null end)  as PUNCHDTM1
    , max(case when rank = 2 then PUNCHDTM else null end)  as PUNCHDTM2
    , max(case when rank = 3 then PUNCHDTM else null end)  as PUNCHDTM3
    , max(case when rank = 4 then PUNCHDTM else null end)  as PUNCHDTM4
    , max(case when rank = 5 then PUNCHDTM else null end)  as PUNCHDTM5
    , max(case when rank = 6 then PUNCHDTM else null end)  as PUNCHDTM6
from employees
group by 1,2,3