mysql - 自定义行编号

我想从表中选择后对数据行进行编号。问题是，我不需要顺序编号，但是应该从1到3依次编号，直到最后，如下所示：

1 | first row
2 | second row
3 | third row
1 | fourth row
2 | and
3 | ....
1
2
3

我正在尝试此查询，但无法正常工作：

mysql -> SET @n = 0;
-> SELECT
CASE
    WHEN nnn = 3 THEN  @n := 0
        ELSE nnn
    END
FROM  (
    SELECT @n := @n + 1 AS nnn FROM mytable
) AS t;

如何使其正常工作？

最佳答案

根据以下答案改编：With MySQL, how can I generate a column containing the record index in a table?

SELECT  MOD(@curRow := @curRow + 1, 3) AS row_number
FROM    mytable m
JOIN    (SELECT @curRow := 0) r;

关于mysql - 自定义行编号，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/12459340/