mysql怎么循环修改表格数据库数据

DECLARE @id INT;
DECLARE @maxId INT;

SET @id = 1;
SELECT @maxId = MAX(id) FROM your_table;

WHILE @id <= @maxId
BEGIN
    UPDATE your_table SET column_name = new_value WHERE id = @id;

    SET @id = @id + 1;
END

DECLARE cur CURSOR FOR SELECT id, column_name FROM your_table;
DECLARE @id INT;
DECLARE @column_name VARCHAR(255);

OPEN cur;
FETCH NEXT FROM cur INTO @id, @column_name;

WHILE @@FETCH_STATUS = 0
BEGIN
    -- 进行更新操作
    UPDATE your_table SET column_name = new_value WHERE id = @id;

    FETCH NEXT FROM cur INTO @id, @column_name;
END

CLOSE cur;
DEALLOCATE cur;

UPDATE your_table
SET column_name = CASE
    WHEN id = 1 THEN new_value_1
    WHEN id = 2 THEN new_value_2
    -- 可以添加更多的条件和对应的新值
    ELSE column_name
    END
WHERE id IN (1, 2, ...); -- 根据需要指定要更新的行