mysql update和case语句结合

做数据库重构之后做数据导入需要将字符串转换为int类型，转换的情况太多于是采用了update和case语句结合，果然省了很多的SQL

UPDATE testSET avg_discount_area = (    CASE    WHEN avg_discount_area ='9.5折以上' THEN 0WHEN avg_discount_area ='（8.0~8.5）折' THEN 1WHEN avg_discount_area ='（6.5~8.0）折' THEN  2WHEN avg_discount_area ='（4.0~6.5）折' THEN 3WHEN avg_discount_area='（2.5~4.0）折' THEN 4WHEN avg_discount_area='（1.0~2.5折）' THEN 5WHEN avg_discount_area = '1折以下' THEN 6WHEN avg_discount_area = '无数据' THEN 7END);