Mysql版本升级到5.7.20版本后，查询的时候出现如下报错:
1055, "Expression #2 of SELECT list is not in GROUP BY
clause and contains nonaggregated column 'xx' which is not functionally dependent on columns in GROUP BY clause;
this is incompatible with sql_mode=only_full_group_by"
解决方式:
用root账户登录：
SET GLOBAL sql_mode=(SELECT REPLACE(@@sql_mode,'ONLY_FULL_GROUP_BY',''));
