MYSQL报错：#1089 - Incorrect prefix key; the used key part isn‘t a string, the used length is longer than the key part, or the storage engine doesn‘t support unique prefix keys
解决办法：
添加索引时大小不要设置即可
MYSQL报错：#1089 - Incorrect prefix key; the used key part isn't a string
原文：https://www.cnblogs.com/liucaixia/p/12010149.html