mysql怎么使某列循环

SELECT 
    id,
    CASE 
        WHEN id % 3 = 1 THEN 'active'
        WHEN id % 3 = 2 THEN 'inactive'
        ELSE 'pending'
    END AS status
FROM my_table;

SELECT 
    id,
    CASE 
        WHEN MOD(id, 3) = 1 THEN 'active'
        WHEN MOD(id, 3) = 2 THEN 'inactive'
        ELSE 'pending'
    END AS status
FROM my_table;

-- 创建序列表
CREATE TABLE sequence_table (
    seq INT AUTO_INCREMENT PRIMARY KEY,
    value ENUM('active', 'inactive', 'pending')
);

-- 插入初始值
INSERT INTO sequence_table (value) VALUES ('active'), ('inactive'), ('pending');

-- 查询并更新主表
UPDATE my_table
JOIN (
    SELECT id, value
    FROM (
        SELECT 
            (@row_number:=@row_number + 1) AS row_number,
            (SELECT value FROM sequence_table WHERE seq = (@row_number % 3) + 1) AS value
        FROM my_table, (SELECT @row_number:=0) AS t
    ) AS subquery
    ON my_table.id = subquery.id
SET my_table.status = subquery.value;