查询表中最新一期资产负债率 ERROR 1055 (42000): Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column

mysql> select ts_code, max(end_date), debt_to_assets from tushare.fina_indicator group by ts_code;
ERROR 1055 (42000): Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'tushare.fina_indicator.ann_date' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by

目标：查询表中最新一期资产负债率

报错内容：ERROR 1055 (42000): Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column

解决办法：参考https://blog.csdn.net/free377096858/article/details/91963406

mysql命令行下执行：

SET GLOBAL sql_mode = 'STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_ENGINE_SUBSTITUTION';

依然存在的问题：查询出来的数据是乱的，不是想要的数据。

select ts_code, max(end_date), debt_to_assets from tushare.fina_indicator group by ts_code;
这种语句要弃用。

况且，set global sql_mode的设置重启后又失灵了。mysql8.0.17版本中/etc/my.cnf里并无设置内容存在，不知如何修改。

问题原因： 

ONLY_FULL_GROUP_BY的意思是：对于GROUP BY聚合操作，如果在SELECT中的列，没有在GROUP BY中出现，那么这个SQL是不合法的，因为列不在GROUP BY从句中，也就是说查出来的列必须在group by后面出现，否则就会报错，或者这个字段出现在聚合函数里面。 

在select指定的字段要么就要包含在Group By语句的后面，作为分组的依据；要么就要被包含在聚合函数中。

  

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; 

查看：

 ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_ENGINE_SUBSTITUTION
第一项默认开启ONLY_FULL_GROUP_BY了,导致出现了错误,需要把它的默认关掉。

解决方法： 
命令行输入 :

SET GLOBAL sql_mode = 'STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_ENGINE_SUBSTITUTION';

不能输入下面的，不然只能起一次作用。后面还是用不了。

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

mysql> select version();
+-----------+
| version() |
+-----------+
| 8.0.17    |
+-----------+
1 row in set (0.00 sec)

mysql> select @@global.sql_mode;
+-----------------------------------------------------------------------------------------------------------------------+
| @@global.sql_mode                                                                                                     |
+-----------------------------------------------------------------------------------------------------------------------+
| ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_ENGINE_SUBSTITUTION |
+-----------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> select @@session.sql_mode;
+-----------------------------------------------------------------------------------------------------------------------+
| @@session.sql_mode                                                                                                    |
+-----------------------------------------------------------------------------------------------------------------------+
| ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_ENGINE_SUBSTITUTION |
+-----------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> set
    -> sql_mode = 'STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_ENGINE_SUBSTITUTION';
Query OK, 0 rows affected (0.00 sec)

mysql> select @@session.sql_mode;
+----------------------------------------------------------------------------------------------------+
| @@session.sql_mode                                                                                 |
+----------------------------------------------------------------------------------------------------+
| STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_ENGINE_SUBSTITUTION |
+----------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> select ts_code, max(end_date), debt_to_assets from tushare.fina_indicator group by ts_code;
+-----------+---------------+----------------+
| ts_code   | max(end_date) | debt_to_assets |
+-----------+---------------+----------------+
| 000001.SZ | 2019-12-31    |         2.3685 |
| 000002.SZ | 2019-12-31    |        75.3555 |
| 000004.SZ | 2019-09-30    |        60.0927 |
| 000005.SZ | 2019-09-30    |        78.5065 |