this is incompatible with sql_mode=only_full_group_by

摘要: ; bad SQL grammar []; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'kjwl.a.description' which is not functionally dependent on columns in GROUP BY clause; this is incompatible w

项目换了个数据库报错：

; bad SQL grammar []; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'kjwl.a.description' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by

主要因为某些 sql group by 语句写得不规范，且数据库设置语法规则比较严格的时候会报错。如果不想改 sql 语句则要改 mysql 的设置：

sql_mode 中去掉 only_full_group_by 项。

可以在 mysql 命令行下输入 SELECT @@sql_mode; 查看当前 sql_mode 有哪些设置。

然后可以执行：

set @@GLOBAL.sql_mode='';

set sql_mode ='STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION';

即重设此值。但这还有一个问题，就是重启 mysql 后设置会被还原。所以上面设置要放到 mysql 的配置文件中，默认是 /etc/my.cnf

在 [mysqld] 项下增加（只要里面没有only_full_group_by 就行了）

# to solve problem: this is incompatible with sql_mode=only_full_group_by

sql_mode=STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION

网上还有说增加的项写成像执行命令的语句一样，但我用自己的版本试则启动失败，用上面那种方式就可以。

参考（有改动）：http://www.cnblogs.com/jim2016/p/6322703.html