报错信息

报错信息及语句如下

SELECT i.sku_id sku_id,a.attr_id attr_id,a.attr_name attr_name, a.attr_value
from pms_sku_info i
LEFT JOIN pms_sku_sale_attr_value a on a.sku_id = i.sku_id
where i.spu_id = 3
GROUP BY a.attr_value;

报错原因

字面翻译： SELECT 列表的表达式 #1 不在 GROUP BY 子句中，并且包含非聚合列“grades.order_id” 它在功能上不依赖于 GROUP BY 子句中的列； 这与 sql_mode=only_full_group_by 不兼容

使用GROUP BY 语句违背了 sql_mode=only_full_group_by。因为mysql版本5.7之后默认的模式是 ONLY_FULL_GROUP_BY

查看官方文档，发现从 MySQL 5.7.5 开始，默认 SQL 模式包括 ONLY_FULL_GROUP_BY。 （在 5.7.5 之前，MySQL 不检测函数依赖，并且默认不启用 ONLY_FULL_GROUP_BY）这可能会导致一些sql语句失效

解决办法

1 临时

执行 SQL ：查询模式

select @@global.sql_mode

得到查询结果：

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

可以看到我们的 sql_mode 中含有 ONLY_FULL_GROUP_BY，因此只要将它去掉即可

执行命令：

SET sql_mode=(SELECT REPLACE(@@sql_mode,'ONLY_FULL_GROUP_BY',''));

注意：

需要注意的是，该修改仅在该次（窗口）有效，只是临时修改

2 永久

Windows 用户

编辑 mysql 配置文件 my.ini，在尾部添加以下内容，重新启动 mysql 即可：

[mysqld] 
sql_mode=STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION

Mac/Linux 用户

需要编辑 /etc/my.cnf 文件，在尾部添加以下内容，重新启动 mysql 即可：

[mysqld] 
sql_mode=STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION

如果该文件不存在，可以新建一个，以下为初始内容：

# Example MySQL config file for medium systems.  
  #  
  # This is for a system with little memory (32M - 64M) where MySQL plays  
  # an important part, or systems up to 128M where MySQL is used together with  
  # other programs (such as a web server)  
  #  
  # MySQL programs look for option files in a set of  
  # locations which depend on the deployment platform.  
  # You can copy this option file to one of those  
  # locations. For information about these locations, see:  
  # http://dev.mysql.com/doc/mysql/en/option-files.html  
  #  
  # In this file, you can use all long options that a program supports.  
  # If you want to know which options a program supports, run the program  
  # with the "--help" option.  
  # The following options will be passed to all MySQL clients  
  [client]
  default-character-set=utf8
  #password   = your_password  
  port        = 3306  
  socket      = /tmp/mysql.sock   
  # Here follows entries for some specific programs  
  # The MySQL server  
  [mysqld]
  character-set-server=utf8
  init_connect='SET NAMES utf8
  port        = 3306  
  socket      = /tmp/mysql.sock  
  skip-external-locking  
  key_buffer_size = 16M  
  max_allowed_packet = 1M  
  table_open_cache = 64  
  sort_buffer_size = 512K  
  net_buffer_length = 8K  
  read_buffer_size = 256K  
  read_rnd_buffer_size = 512K  
  myisam_sort_buffer_size = 8M  
  character-set-server=utf8  
  init_connect='SET NAMES utf8' 
# Don't listen on a TCP/IP port at all. This can be a security enhancement,  
# if all processes that need to connect to mysqld run on the same host.  
# All interaction with mysqld must be made via Unix sockets or named pipes.  
# Note that using this option without enabling named pipes on Windows  
# (via the "enable-named-pipe" option) will render mysqld useless!  
#   
#skip-networking  
  
  # Replication Master Server (default)  
  # binary logging is required for replication  
  log-bin=mysql-bin  
    
    # binary logging format - mixed recommended  
    binlog_format=mixed  
      

3 自用

或者可以像我这样使用

SELECT GROUP_CONCAT( i.sku_id) sku_id,
GROUP_CONCAT(DISTINCT a.attr_id) attr_id,
GROUP_CONCAT(DISTINCT a.attr_name) attr_name, a.attr_value
from pms_sku_info i
LEFT JOIN pms_sku_sale_attr_value a on a.sku_id = i.sku_id
where i.spu_id = 3
GROUP BY a.attr_value;

使用 GROUP_CONCAT函数将需要查询的结果包裹，这样就不会报错（不清楚原因）

查询结果显示如下：