如何使用MySQL存储过程的游标创建逗号分隔值？

CREATE PROCEDURE get_comma_separated_values()
BEGIN
    -- 存储过程的逻辑
END;

DECLARE cursor_name CURSOR FOR SELECT column_name FROM table_name;

OPEN cursor_name;

DECLARE done INT DEFAULT FALSE;
DECLARE comma_separated_values VARCHAR(255) DEFAULT '';

-- 游标循环
WHILE NOT done DO
    FETCH cursor_name INTO column_variable;

    -- 检查是否还有更多数据
    IF NOT done THEN
        -- 将数据添加到逗号分隔值中
        SET comma_separated_values = CONCAT(comma_separated_values, column_variable, ',');
    END IF;
END WHILE;

CLOSE cursor_name;

SELECT comma_separated_values;

CREATE PROCEDURE get_comma_separated_values()
BEGIN
    DECLARE done INT DEFAULT FALSE;
    DECLARE comma_separated_values VARCHAR(255) DEFAULT '';
    DECLARE column_variable VARCHAR(255);

    -- 声明游标
    DECLARE cursor_name CURSOR FOR SELECT column_name FROM table_name;

    -- 打开游标
    OPEN cursor_name;

    -- 游标循环
    WHILE NOT done DO
        FETCH cursor_name INTO column_variable;

        -- 检查是否还有更多数据
        IF NOT done THEN
            -- 将数据添加到逗号分隔值中
            SET comma_separated_values = CONCAT(comma_separated_values, column_variable, ',');
        END IF;
    END WHILE;

    -- 关闭游标
    CLOSE cursor_name;

    -- 返回逗号分隔值
    SELECT comma_separated_values;
END;