mysql - 为 MySQL 提供手动输入的行列表以进行左连接？

Question

我的 Google-Fu 在这方面很弱，所以也许你们都可以提供帮助。

如果你想选择多列，你可以这样做......

选择“something”作为用户名，“fooBar”作为典型说法

你会得到:

+----------------+-----------------+
|    userName    |   typicalSaying |
+----------------+-----------------+
|   something    |    fooBar       |
+----------------+-----------------+

但是，如何对行执行上述操作？

EG:

SELECT someLine, effy.text from table
LEFT JOIN (SELECT 'a' as text UNION 'b' UNION 'c') as effy 

编辑:得到像这样的结果..

+----------------+--------------+
|    someLine    |   effy.text  |
+----------------+--------------+
|   entryA       |    a         |
|   entryA       |    b         |
|   entryA       |    c         |
+----------------+--------------+

Answer 1

你就快到了:

SELECT someLine, effy.text
FROM table
LEFT JOIN (
  SELECT 'a' as text
  UNION ALL
  SELECT 'b'
  UNION ALL
  SELECT 'c'
) as effy