根据列值db2将行拆分为多行

Question

我有以下数据：

Sr no....EMP_ID....Location...Period1....Value1....Period2....Value2....Period3....Value3
...1......Emp001....India........Salary.....10000.....Bonus.....1000.......Bonus code...AB
...2......Emp002....UK...........Salary.....20000.....Bonus.....2000.......Bonus code...CD

我希望输出如下：

Sr no....EMP_ID....Location....Period...Value
....1......Emp001....India.......Salary.....10000
....2......Emp001....India.......Bonus.....1000
....3......Emp001....India.......Bonus Code.....AB
....4......Emp002....UK.......Salary.....20000
....5......Emp002....UK.......Bonus.....2000
....6......Emp002....UK.......Bonus Code.....CD

Answer 1

这是一项非操作性操作。您可以使用union all：

执行所需操作

select EmpNo, Location, Period1 as period, Value1 as Value
from data
union all
select EmpNo, Location, Period2 as period, Value2 as Value
from data
union all
select EmpNo, Location, Period3 as period, Value3 as Value
from data;

某些数据库直接支持unpivot以及其他方法。但是，以上是ANSI标准SQL。