如何按特定字符“动态”拆分varchar列？

SELECT SUBSTRING_INDEX(column_name, ',', 1) AS part1,
       SUBSTRING_INDEX(SUBSTRING_INDEX(column_name, ',', 2), ',', -1) AS part2,
       SUBSTRING_INDEX(SUBSTRING_INDEX(column_name, ',', 3), ',', -1) AS part3,
       ...

SET @str = column_name;
SET @delimiter = ',';
SET @length = LENGTH(@str);
SET @i = 1;

WHILE @i <= @length DO
    SET @part = SUBSTRING_INDEX(@str, @delimiter, 1);
    SET @str = SUBSTRING(@str, LENGTH(@part) + 2);
    SET @i = @i + 1;
    
    -- 在此处可以对拆分后的部分进行处理，例如插入到另一个表中或进行其他操作
    -- INSERT INTO another_table (column_name) VALUES (@part);
    
    -- 输出拆分后的部分
    SELECT @part AS part;
END WHILE;