在两行中写入两个非空值

Question

当 A 列和 B 列中存在非空值时，我正在寻找将一行中的值拆分为两行的有效方法

Answer 1

这是一种选择；合并两个集合，return 只有那些 cola 不为空的集合。

示例数据：

SQL> with test (cola, colb, colc) as
  2    (select 1, null, 'AA' from dual union all
  3     select 2,    6, 'BB' from dual union all
  4     select 3, null, 'CC' from dual union all
  5     select 4, null, 'DD' from dual union all
  6     select 5, null, 'EE' from dual
  7    ),

查询从这里开始：

  8  temp as
  9    (select cola, colc from test
 10     union all
 11     select colb, colc from test
 12    )
 13  select cola, colc
 14  from temp
 15  where cola is not null
 16  order by colc, cola;

      COLA COLC
---------- ----------
         1 AA
         2 BB
         6 BB
         3 CC
         4 DD
         5 EE

6 rows selected.

SQL>

您评论说“输入”是许多连接和嵌套查询的结果；没问题 - 只需将 复杂的 查询用作 CTE：

with test as
  (your complicated query with joins and nested queries goes here),
temp as 
   the rest is copy/paste from above

Answer 2

你可以UNPIVOT:

SELECT output, col3
FROM   table_name
UNPIVOT (
  output FOR key IN (cola, colb)
)

或者，将 table_name 替换为包含您的查询的 () 方括号。其中，对于示例数据：

其中，对于示例数据：

CREATE TABLE table_name (cola, colb, col3) AS
SELECT LEVEL, CASE LEVEL WHEN 2 THEN 6 END, CHR(64+LEVEL) || CHR(64 + LEVEL)
FROM   DUAL
CONNECT BY LEVEL <= 5;

输出：

OUTPUT COL3

1 AA

2 BB

6 BB

3 CC

4 DD

5 EE

db<>fiddle here

在两行中写入两个非空值

writing two Non Null values in two rows

sql

oracle

union

join