[root@uat01 ~]# cat InstallMysql01.sh

#!/bin/bash

#--

#旅行者-Travel

#.安装wget

yum -y install  wget

#、下载mysql的yum源

URL="https://repo.mysql.com//mysql80-community-release-el7-1.noarch.rpm"

wget $URL -P /etc/yum.repos.d/

yum -y install yum-utils   #如果没有该包，下边执行yum-config-manager不生效

yum -y install /etc/yum.repos.d/mysql80-community-release-el7-.noarch.rpm

    if [ $? -eq  ];then

        rm -rf /etc/yum.repos.d/mysql80-community-release-el7-.noarch*

    fi

yum-config-manager --disable mysql80-community

yum-config-manager --enable mysql57-community

yum -y install mysql-community-server

    sleep

    systemctl start mysqld

    systemctl enable mysqld

    systemctl status mysqld

    if [ $? -eq  ];then

        echo -e "install succefull"

        result="`grep 'temporary password' /var/log/mysqld.log`"

        p1="`echo $result |awk '{print $NF}'`"

        echo "数据库密码为:$p1"

    fi

[root@uat01 ~]# 

install succefull

数据库密码为:9aTR&ok>f;1K

[root@uat01 ~]# mysql -uroot -p

Enter password:

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is

Server version: 5.7.

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

Oracle is a registered trademark of Oracle Corporation and/or its

affiliates. Other names may be trademarks of their respective

owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> set global validate_password_policy=;

Query OK,  rows affected (0.00 sec)

mysql> set global validate_password_length=;

Query OK,  rows affected (0.00 sec)

mysql>  alter user 'root'@'localhost' identified by 'Yanglt123.';

Query OK,  rows affected (0.00 sec)

mysql>  flush privileges;

Query OK,  rows affected (0.00 sec)

mysql> quit

[root@uat01 ~]# mysql -uroot -p

.....

Server version: 5.7. MySQL Community 
......

mysql> show variables like 'validate_password%';

+--------------------------------------+-------+

| Variable_name                        | Value |

+--------------------------------------+-------+

| validate_password_check_user_name    | OFF   |

| validate_password_dictionary_file    |       |

| validate_password_length             |      |

| validate_password_mixed_case_count   |      |

| validate_password_number_count       |      |

| validate_password_policy             | LOW   |

| validate_password_special_char_count |      |

+--------------------------------------+-------+

 rows in set (0.00 sec)

mysql> 

mysql> set global validate_password_policy=;

Query OK,  rows affected (0.00 sec)

mysql> set global validate_password_length=;

Query OK,  rows affected (0.00 sec),

mysql>  flush privileges;

Query OK,  rows affected (0.00 sec)

mysql> alter user 'root'@'localhost' identified by ''; #测试发现密码长度最少为4位

Query OK,  rows affected (0.00 sec)

mysql> flush privileges;

Query OK,  rows affected (0.01 sec)

mysql> quit

Bye

[root@uat01 ~]# mysql -p

Enter password:

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is

Server version: 5.7. MySQL Community Server (GPL)

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

Oracle is a registered trademark of Oracle Corporation and/or its

affiliates. Other names may be trademarks of their respective

owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>