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 )