小试下新博客，一个列传行的SQL

源表的结构如下：

create table TAB_SAL
(
  empno         NUMBER,
  income_type   NUMBER,
  income_amount NUMBER
)

列转行SQL：

select t.empno,
       (select sum(t1.income_amount)
          from TAB_SAL t1
         where t1.income_type = 11
           and t1.empno = t.empno),
       (select sum(t1.income_amount)
          from TAB_SAL t1
         where t1.income_type = 22
           and t1.empno = t.empno),
       (select sum(t1.income_amount)
          from TAB_SAL t1
         where t1.income_type = 33
           and t1.empno = t.empno),
       (select sum(t1.income_amount)
          from TAB_SAL t1
         where t1.income_type = 44
           and t1.empno = t.empno)

  from TAB_SAL t
 group by t.empno

select t.empno,
       (select t1.income_amount
          from TAB_SAL t1
         where t1.empno = t.empno
           and t1.income_type = 11),
       (select t1.income_amount
          from TAB_SAL t1
         where t1.empno = t.empno
           and t1.income_type = 22),
       (select t1.income_amount
          from TAB_SAL t1
         where t1.empno = t.empno
           and t1.income_type = 33),
       (select t1.income_amount
          from TAB_SAL t1
         where t1.empno = t.empno
           and t1.income_type = 44)

  from TAB_SAL t

 group by t.empno

一个加sum一个不加，结果都可以，我认为分组完毕后select后面只能出现每组最小维的一行数据，只要保证这个我觉得就可以。