postgresql 选择没有表格的硬编码值

Select hardcoded values without table

提问by Richard Knop

I need to run a select without actually connecting to any table. I just have a predefined hardcoded set of values I need to loop over:

我需要在不实际连接到任何表的情况下运行选择。我只有一组需要循环的预定义硬编码值：

foo
bar
fooBar

And I want to loop through those values. I can do:

我想遍历这些值。我可以：

select 'foo', 'bar', 'fooBar';

But this returns it as one row:

但这将它作为一行返回：

 ?column? | ?column? | ?column? 
----------+----------+----------
 foo      | bar      | fooBar
(1 row)

I am using Postgresql.

我正在使用 Postgresql。

回答by Clodoaldo Neto

select a
from (
    values ('foo'), ('bar'), ('fooBar')
) s(a);

http://www.postgresql.org/docs/current/static/queries-values.html

http://www.postgresql.org/docs/current/static/queries-values.html

回答by Vivek S.

Using unnest()

使用 unnest()

expand an array to a set of rows

将数组扩展为一组行

select unnest(array['foo', 'bar', 'fooBar']);

demo

演示