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今天在使用MySQL命令行进行分组时报错:
ERROR 1055 (42000): Expression #1 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'database_tl.emp.id' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by
原因:
看一下group by的语法:
select 选取分组中的列+聚合函数 from 表名称 group by 分组的列
从语法格式来看,是先有分组,再确定检索的列,检索的列只能在参加分组的列中选。
查找原因:
查看mysql版本命令:select version();
查看sql_model参数命令:
SELECT @@GLOBAL.sql_mode;
SELECT @@SESSION.sql_mode;
发现:
ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
第一项默认开启ONLY_FULL_GROUP_BY,
解决方法:
1.只选择出现在group by后面的列,或者给列增加聚合函数;
2.命令行输入:
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';
如果上面设置完成后依然报错,这里执行下面的SQL,将全局设置更改,然后必须关闭现有的连接,重新打开连接后查询即可
set global sql_mode='STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION';
默认关掉ONLY_FULL_GROUP_BY!
更改完之后可以查看sql_mode:
SELECT @@GLOBAL.sql_mode;
SELECT @@SESSION.sql_mode;
相关参考网址:
https://segmentfault.com/a/1190000005936172
http://blog.csdn.net/u014520745/article/details/76056170
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