题解 | #修复串列了的记录#
修复串列了的记录
http://www.nowcoder.com/practice/a5475ed3b5ab4de58e2ea426b4b2db76
SELECT
exam_id,
SUBSTRING_INDEX(SUBSTRING_INDEX(tag,',',1),',',-1) as tag,
SUBSTRING_INDEX(SUBSTRING_INDEX(tag,',',2),',',-1) as difficulty,
SUBSTRING_INDEX(tag,',',-1) as duration
from examination_info
#查找录错了的记录
where tag LIKE '%,%';