搭建博客时,被mysql的sql_mode中ONLY_FULL_GROUP_BY坑倒了

warning: 这篇文章距离上次修改已过310天,其中的内容可能已经有所变动。

1、背景

前两天在阿里云服务器上搭建了自己的博客,一切都很顺利,今天在点击归档按钮时,发现是报404。于是我把solo代码在本地运行起来,用本地的mysql数据库,看是否有同样的问题,结果是可以正常访问的。那就看看服务器上的solo日志呗,结果发现了以下报错:

Caused by: org.b3log.latke.repository.RepositoryException: java.sql.SQLSyntaxErrorException: Expression #20 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'solo.aa.oId' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by

原来,这个问题出现在MySQL5.7后版本上,默认的sql_mode值是这样的:

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

那么sql_mode 有哪些配置?都代表什么意思?
2、sql_mode 配置解析

ONLY_FULL_GROUP_BY

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。简而言之,就是SELECT后面接的列必须被GROUP BY后面接的列所包含。如:

select a,b from table group by a,b,c; (正确)
select a,b,c from table group by a,b; (错误)

这个配置会使得GROUP BY语句环境变得十分狭窄,所以一般都不加这个配置

NO_AUTO_VALUE_ON_ZERO

该值影响自增长列的插入。默认设置下,插入0或NULL代表生成下一个自增长值。(不信的可以试试,默认的sql_mode你在自增主键列设置为0,该字段会自动变为最新的自增值,效果和null一样),如果用户希望插入的值为0(不改变),该列又是自增长的,那么这个选项就有用了。

STRICT_TRANS_TABLES

在该模式下,如果一个值不能插入到一个事务表中,则中断当前的操作,对非事务表不做限制。(InnoDB默认事务表,MyISAM默认非事务表;MySQL事务表支持将批处理当做一个完整的任务统一提交或回滚,即对包含在事务中的多条语句要么全执行,要么全部不执行。非事务表则不支持此种操作,批处理中的语句如果遇到错误,在错误前的语句执行成功,之后的则不执行;MySQL事务表有表锁与行锁非事务表则只有表锁)

NO_ZERO_IN_DATE

在严格模式下,不允许日期和月份为零

NO_ZERO_DATE

设置该值,mysql数据库不允许插入零日期,插入零日期会抛出错误而不是警告。

ERROR_FOR_DIVISION_BY_ZERO

在INSERT或UPDATE过程中,如果数据被零除,则产生错误而非警告。如 果未给出该模式,那么数据被零除时MySQL返回NULL

NO_AUTO_CREATE_USER

禁止GRANT创建密码为空的用户

NO_ENGINE_SUBSTITUTION

如果需要的存储引擎被禁用或未编译,那么抛出错误。不设置此值时,用默认的存储引擎替代,并抛出一个异常

PIPES_AS_CONCAT

将”||”视为字符串的连接操作符而非或运算符,这和Oracle数据库是一样的,也和字符串的拼接函数Concat相类似

ANSI_QUOTES

启用ANSI_QUOTES后,不能用双引号来引用字符串,因为它被解释为识别符
3、测试

本地起一个数据库,先查看sql_mode模式:

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

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

创建一个测试的表:

mysql> CREATE TABLE IF NOT EXISTS demo(

->    `id` INT UNSIGNED AUTO_INCREMENT,                     
->    `rank` VARCHAR(100) NOT NULL,                         
->    `name` VARCHAR(40) NOT NULL,                          
->    `gender` TINYINT NOT NULL,                            
->    PRIMARY KEY ( `id` )                                  
-> )ENGINE=InnoDB DEFAULT CHARSET=utf8;                     

Query OK, 0 rows affected (0.02 sec)

mysql>
mysql> show tables;
+----------------+
| Tables_in_test |
+----------------+
| demo |
+----------------+
1 row in set (0.00 sec)

mysql> desc demo;
FieldTypeNullKeyDefaultExtra
idint(10) unsignedNOPRINULLauto_increm
rankvarchar(100)NO NULL
namevarchar(40)NO NULL
gendertinyint(4)NO NULL

4 rows in set (0.01 sec)

插入测试数据:

mysql> insert into demo values(1, 'A', 'coderaction1', '20');
Query OK, 1 row affected (0.01 sec)

mysql> insert into demo values(2, 'B', 'coderaction2', '21');
Query OK, 1 row affected (0.00 sec)

mysql> insert into demo values(3, 'A', 'coderaction3', '22');
Query OK, 1 row affected (0.00 sec)

mysql> insert into demo values(4, 'C', 'coderaction4', '23');
Query OK, 1 row affected (0.00 sec)

mysql> insert into demo values(5, 'A', 'coderaction5', '21');
Query OK, 1 row affected (0.00 sec)

mysql> insert into demo values(6, 'C', 'coderaction6', '28');
Query OK, 1 row affected (0.01 sec)

mysql>
mysql> select * from demo;
+----+------+--------------+--------+
| id | rank | name | gender |
+----+------+--------------+--------+
| 1 | A | coderaction1 | 20 |
| 2 | B | coderaction2 | 21 |
| 3 | A | coderaction3 | 22 |
| 4 | C | coderaction4 | 23 |
| 5 | A | coderaction5 | 21 |
| 6 | C | coderaction6 | 28 |
+----+------+--------------+--------+
6 rows in set (0.00 sec)

分别执行以下sql命令:

mysql> select count(id) from demo order by rank;
+-----------+
| count(id) |
+-----------+
| 6 |
+-----------+
1 row in set (0.01 sec)

mysql> select count(id) from demo group by rank;
+-----------+
| count(id) |
+-----------+
| 3 |
| 1 |
| 2 |
+-----------+
3 rows in set (0.00 sec)

mysql> select count(rank),id from demo group by rank;
+-------------+----+
| count(rank) | id |
+-------------+----+
| 3 | 1 |
| 1 | 2 |
| 2 | 4 |
+-------------+----+
3 rows in set (0.00 sec)

mysql> select count(rank),id from demo group by id;
+-------------+----+
| count(rank) | id |
+-------------+----+
| 1 | 1 |
| 1 | 2 |
| 1 | 3 |
| 1 | 4 |
| 1 | 5 |
| 1 | 6 |
+-------------+----+
6 rows in set (0.00 sec)

mysql>

可以看到上面四个sql都执行成功。

修改sql_mode,临时修改sql_mode方式有两种,一种是设置当前会话连接的session级别的sql_mode,另一个是global级别的sql_mode。
session级别

先来看看session级别的sql_mode,设置方式有两种:

mysql> set session sql_mode='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';
Query OK, 0 rows affected (0.00 sec)

mysql> set @@session.sql_mode='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';
Query OK, 0 rows affected (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_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION

1 row in set (0.00 sec)

设置session级别sql_mode,当前session级别查询到新的,下次重连后失效。
global级别

再看看global级别的sql_mode,设置方式有两种:

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';
Query OK, 0 rows affected (0.00 sec)

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';
Query OK, 0 rows affected (0.00 sec)

mysql> select @@global.sql_mode;
@@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 row in set (0.00 sec)

设置global级别sql_mode,当前session级别查询到还是旧的,所以执行命令时,还是按照旧配置。下次重连后利用新配置。

当我们设置完上面session级别的sql_mode,在其中加ONLY_FULL_GROUP_BY后,执行测试sql语句报错:

mysql> select count(rank),id from demo group by rank;
ERROR 1055 (42000): Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'test.demo.id' which is not functionally dependen
t on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by
mysql> select count(rank),id from demo group by id;
+-------------+----+
| count(rank) | id |
+-------------+----+
| 1 | 1 |
| 1 | 2 |
| 1 | 3 |
| 1 | 4 |
| 1 | 5 |
| 1 | 6 |
+-------------+----+
6 rows in set (0.00 sec)

这也验证了:SELECT后面接的列必须被GROUP BY后面接的列所包含。

注意:通过session和global设置临时生效的,即当mysql重启后,都会失效。需要在mysql启动配置文件中默认设置。
4、解决办法

除了上面测试时用到的临时解决的两种方法。要想mysql重启后依然生效,需要在mysql的配置文件,一般是my.cnf中的[mysqld]下面加sql_mode配置。因为我使用的是k8s部署的mysql,镜像安装和在宿主机上通过软件包安装有一定差别。但最终还是更改的my.cnf。

kubectl exec -ti mysql-75797cf796-84rdl bash
root@mysql-75797cf796-84rdl:/#
root@mysql-75797cf796-84rdl:/# cat /etc/mysql/my.cnf

Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.

.....

!includedir /etc/mysql/conf.d/
!includedir /etc/mysql/mysql.conf.d/

在这里插入图片描述
可以看到这里包含了两个目录下的文件,查看一下,mysql.conf.d下,发现有我们需要更改的文件

cat /etc/mysql/mysql.conf.d/mysqld.cnf

查看并将该文件用kubectl cp命令拷贝到宿主机上,修改后最终要挂载进入pod里。

kubectl cp default/mysql-75797cf796-84rdl:/etc/mysql/mysql.conf.d/mysqld.cnf /data/blog-solo/mysql-config/mysqld.cnf

修改后文件如下,主要关注sql_mode

root@mysql-75797cf796-84rdl:/# cd /etc/mysql/mysql.conf.d/
root@mysql-75797cf796-84rdl:/etc/mysql/mysql.conf.d# ls -l
total 4
-rw-r--r-- 1 root root 1671 Oct 26 11:40 mysqld.cnf
root@mysql-75797cf796-84rdl:/etc/mysql/mysql.conf.d# cat mysqld.cnf

Copyright (c) 2014, 2016, Oracle and/or its affiliates. All rights reserved.

...

[mysqld]
pid-file = /var/run/mysqld/mysqld.pid
socket = /var/run/mysqld/mysqld.sock
datadir = /var/lib/mysql
sql_mode = STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION

log-error = /var/log/mysql/error.log

By default we only accept connections from localhost

bind-address = 127.0.0.1

Disabling symbolic-links is recommended to prevent assorted security risks

symbolic-links=0
root@mysql-75797cf796-84rdl:/etc/mysql/mysql.conf.d#

最后修改mysql-deployment:

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: mysql
spec:
replicas: 1
template:

metadata:
  labels:
    name: mysql
spec:
  containers:
  - name: mysql 
    image: mysql:5.7.28 
    imagePullPolicy: IfNotPresent
    ports:
    - containerPort: 3306
    env:
    - name: MYSQL_ROOT_PASSWORD
      value: "password"
    volumeMounts:
    - name: mysql-config
      mountPath: /etc/mysql/mysql.conf.d
    - name: mysql-data
      mountPath: /var/lib/mysql
  volumes:
  - name: mysql-config
    hostPath:
      path: /data/blog-solo/mysql-config/
  - name: mysql-data
    hostPath:
      path: /data/blog-solo/mysql-data/

注意要把配置文件和数据都挂载到宿主机上,否则pod重启后就会丢失配置和数据。

作者:码农实战
链接:http://www.imooc.com/article/294753
来源:慕课网

版权声明 ▶ 本网站名称:我的学习笔记
▶ 本文链接:https://ooolo.net/article/48.html
▶ 本网站的文章部分内容可能来源于网络,仅供大家学习与参考,如有侵权,请联系站长进行核实删除。
▶ 转载本站文章需要遵守:商业转载请联系站长,非商业转载请注明出处!!!

none
最后修改于:2023年04月29日 17:56

添加新评论

icon_mrgreen.pngicon_neutral.pngicon_twisted.pngicon_arrow.pngicon_eek.pngicon_smile.pngicon_confused.pngicon_cool.pngicon_evil.pngicon_biggrin.pngicon_idea.pngicon_redface.pngicon_razz.pngicon_rolleyes.pngicon_wink.pngicon_cry.pngicon_surprised.pngicon_lol.pngicon_mad.pngicon_sad.pngicon_exclaim.pngicon_question.png