Expression #1 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'userinfo.
安裝了mysql5.7，用group by 查詢時拋出如下異常：
Expression #3 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'userinfo.t_long.user_name' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by- 1
原因：
MySQL 5.7.5和up實現了對功能依賴的檢測。如果啓用了only_full_group_by SQL模式(在默認情況下是這樣)，那麼MySQL就會拒絕選擇列表、條件或順序列表引用的查詢，這些查詢將引用組中未命名的非聚合列，而不是在功能上依賴於它們。(在5.7.5之前，MySQL沒有檢測到功能依賴項，only_full_group_by在默認情況下是不啓用的。關於前5.7.5行爲的描述，請參閱MySQL 5.6參考手冊。)
執行以下個命令，可以查看 sql_mode 的內容。
mysql> SHOW SESSION VARIABLES;- 1
mysql> SHOW GLOBAL VARIABLES;- 1
mysql> select @@sql_mode;- 1
可見session和global 的sql_mode的值都爲： 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
only_full_group_by說明：
only_full_group_by ：使用這個就是使用和oracle一樣的group 規則, select的列都要在group中,或者本身是聚合列(SUM,AVG,MAX,MIN) 才行，其實這個配置目前個人感覺和distinct差不多的，所以去掉就好
官網摘抄：
官網：ONLY_FULL_GROUP_BY
Reject queries for which the select list, HAVING condition, or ORDER BY list refer to nonaggregated columns that are neither named in the GROUP BY clause nor are functionally dependent on (uniquely determined by) GROUP BY columns.
As of MySQL 5.7.5, the default SQL mode includes ONLY_FULL_GROUP_BY. (Before 5.7.5, MySQL does not detect functional dependency and ONLY_FULL_GROUP_BY is not enabled by default. For a description of pre-5.7.5 behavior, see the MySQL 5.6 Reference Manual.)
A MySQL extension to standard SQL permits references in the HAVING clause to aliased expressions in the select list. Before MySQL 5.7.5, enabling ONLY_FULL_GROUP_BY disables this extension, thus requiring the HAVING clause to be written using unaliased expressions. As of MySQL 5.7.5, this restriction is lifted so that the HAVING clause can refer to aliases regardless of whether ONLY_FULL_GROUP_BY is enabled.
解決：
執行以下兩個命令：
mysql> 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';- 1
mysql> set session sql_mode='STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION';- 1
這兩個命令，去掉 sql_mode 的 ONLY_FULL_GROUP_BY
見其他文章有說： 直接修改mysql配置文件（我的系統是Ubuntu16.04的，在/etc/mysql/mysql.conf.d/mysqld.cnf 中並沒有sql_mode這個配置，所以直接加上就好，如果是其他系統有得修改就不用添加了）
這個方法暫時沒有式。
mysql 配置信息讀取順序。
①ps aux|grep mysql|grep ‘my.cnf’
②mysql –help|grep ‘my.cnf’
/etc/my.cnf, /etc/mysql/my.cnf, /usr/local/etc/my.cnf, ~/.my.cnf 這些就是mysql默認會搜尋my.cnf的目錄，順序排前的優先。mysql按照上面的順序加載配置文件，後面的配置項會覆蓋前面的。
如果沒有該文件可以自定義一個文件。然後回默認讀取配置中的內容）
查看你需要修改的是哪個配置文件。我只有/etc/my.cnf 只修改這個文件即可
配置文件my.cnf通常會分成好幾部分，如[client]，[mysqld], [mysql]等等。MySQL程序通常是讀取與它同名的分段部分，例如服務器mysqld通常讀取[mysqld]分段下的相關配置項。如果配置項位置不正確，該配置是不會生效的
這個語句沒試過，先記錄：(標識:能用->重啓服務器之後,失敗)
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';- 1
去掉ONLY_FULL_GROUP_BY即可正常執行sql.
經典常用方法(更改配置)
vim /etc/my.cnf
添加
sql_mode = "STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"# For advice on how to change settings please see # http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html [mysqld] character_set_server=utf8 init_connect='SET NAMES utf8' sql_mode = "STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"