mysql 表关联查询报错 ERROR 1267 (HY000)
解决翻案：http://*.com/questions/1008287/illegal-mix-of-collations-mysql-error
即：
SET collation_connection = 'utf8_general_ci'; ALTER DATABASE db CHARACTER SET utf8 COLLATE utf8_general_ci; ALTER TABLE table CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;