Question

我正在尝试将“literal”多列表用于Oracle 11g的连接查询。

这是我提出的最好的，基于from HERE（ this answer建议使用更好的语法，但据我所知，它仅适用于单列表：

SELECT * from
(
 -- The ugly... it burns...
 select 'APPLE' as n, 'FRUIT' as m from dual
 union all select 'CARROT' as n, 'VEGGIE' as m from dual
 union all select 'PEACH' as n, 'FRUIT' as m from dual
 union all select 'CUCUMBER' as n, 'VEGGIE' as m from dual
 union all select 'ORANGE' as n, 'FRUIT' as m from dual
)

在Oracle中创建多行，多列文字表是否有一种不那么难看的方式？不幸的是，我无法创建临时表。

<rant>正如我所预料的那样，PostgreSQL有一个this answer，但甲骨文很乱。</rant>

编辑：我曾尝试将nice, sane syntax for literal tables作为row-value constructor syntax，但这也不起作用：select n,m from dual where (n,m) in (...)给我一个无效的标识符错误。

Answer 1

对于两列，您可以使用ODCIObjectList：

select objectschema m, objectname n
  from table(sys.ODCIObjectList(
    sys.odciobject('APPLE', 'FRUIT'), 
    sys.odciobject('CARROT', 'VEGGIE'),
    sys.odciobject('PEACH', 'FRUIT'),
    sys.odciobject('CUCUMBER', 'VEGGIE'),
    sys.odciobject('ORANGE', 'FRUIT')));

M          N         
---------- ----------
APPLE      FRUIT     
CARROT     VEGGIE    
PEACH      FRUIT     
CUCUMBER   VEGGIE    
ORANGE     FRUIT

有关更多列，您可以定义自己的类型：

create type t as object (a varchar2(10), b varchar2(10), c number);
create type tt as table of t;

select * from table( tt (
    t('APPLE', 'FRUIT', 1),
    t('APPLE', 'FRUIT', 1122), 
    t('CARROT', 'VEGGIE', 3),
    t('PEACH', 'FRUIT', 104),
    t('CUCUMBER', 'VEGGIE', 5),
    t('ORANGE', 'FRUIT', 6) ) )

A          B                   C
---------- ---------- ----------
APPLE      FRUIT               1 
APPLE      FRUIT            1122 
CARROT     VEGGIE              3 
PEACH      FRUIT             104 
CUCUMBER   VEGGIE              5 
ORANGE     FRUIT               6

Answer 2

对于许多列，您可以像这样加入

SELECT a.v field1, b.v field2
  FROM (SELECT column_value v, rownum r
          FROM TABLE(sys.odcivarchar2list('abc', 'def', 'ghi'))) a
  JOIN (SELECT column_value v, rownum r
          FROM TABLE(sys.odcivarchar2list('abc', 'def', 'ghi'))) b ON a.r = b.r

在Oracle 11g查询中使用多列，多行表文字是否有一种非丑陋的方式？

2 个答案: