大手子们,请教一条返回固定条数记录的 sql 怎么写

不懂 sql

比如我要返回 4 条记录 不符合条件的 NULL 填充

我自己瞎凑出来的功能是实现了,但是好像太复杂了,是不是有简单的办法

SELECT guild FROM ( SELECT guild, 1 as SortOrder FROM characters WHERE id = 1 UNION SELECT NULL, 2 ORDER BY SortOrder LIMIT 1 ) UNION ALL SELECT guild FROM ( SELECT guild, 1 as SortOrder FROM characters WHERE id = 2 UNION SELECT NULL, 2 ORDER BY SortOrder LIMIT 1 ) UNION ALL SELECT guild FROM ( SELECT guild, 1 as SortOrder FROM characters WHERE id = 3 UNION SELECT NULL, 2 ORDER BY SortOrder LIMIT 1 ) UNION ALL SELECT guild FROM ( SELECT guild, 1 as SortOrder FROM characters WHERE id = 4 UNION SELECT NULL, 2 ORDER BY SortOrder LIMIT 1 )