题解|拆分| #修复串列了的记录#
修复串列了的记录
https://www.nowcoder.com/practice/a5475ed3b5ab4de58e2ea426b4b2db76
SELECT exam_id, substring_index(tag, ',', 1) AS tag, substring_index(substring_index(tag, ',', 2), ',', -1) AS difficulty, CAST( substring_index(tag, ',', -1) AS DECIMAL ) AS duration FROM examination_info WHERE tag LIKE '%,%';