大手子们,请教一条返回固定条数记录的 sql 怎么写

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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
)

3 replies • 2020-07-11 17:51:35 +08:00