作者： admin

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MySQL
https://downloads.mysql.com/archives/installer/
官方工具集 https://downloads.mysql.com/archives/
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忘记MySQL 密码
先关闭mysql服务,再带参数启动
./mysqld_safe –skip-grant-tables
进mysql命令行
mysql -uroot -p
执行更新
update mysql.user SET Password=PASSWORD(‘password123′) where USER=’root’;
update mysql.user set authentication_string=password(‘password123′) where user=’root’;
update mysql.user set grant_priv=’Y’ where user=’root’ and host=’%’;
grant all privileges on *.* to root@”%” identified by “Password123”;
grant all privileges on *.* to root@”127.0.0.1″ identified by “Password123” WITH GRANT OPTION;
select host,user,password,authentication_string from mysql.user;
flush privileges;
退出重启MySQL,密码已变更为password123
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PQSQL
https://www.postgresql.org/download/

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Microsoft® SQL Server® 2017 Express
https://www.microsoft.com/zh-CN/download/details.aspx?id=55994
官方管理工具 SQL Server Management Studio
https://docs.microsoft.com/zh-CN/sql/ssms/download-sql-server-management-studio-ssms?view=sql-server-2017

Yes, SQL Server 2008 R2 Express with Tools and SQL Server 2008 R2 Express with Advanced Services will allow 10GB databases as well.
SQL Server 2008 R2 Express is still limited to 1 CPU and 1 GB or RAM.
免费版有内存使用和数据库大小的限制， 10G数据库，1G内存，1CPU，
作为测试，要用那么多资源干啥？？

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# 在Linux中安装SQLServer
https://learn.microsoft.com/zh-cn/sql/linux/quickstart-install-connect-docker
sql-server-management-studio
https://learn.microsoft.com/zh-cn/ssms/download-sql-server-management-studio-ssms#download-ssms
https://aka.ms/ssmsfullsetup

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Oracle Database XE , Free Oracle Database for Everyone
https://www.oracle.com/database/technologies/appdev/xe.html
Oracle SQL Developer
https://www.oracle.com/cn/tools/downloads/oracle-sql-developer-download.html

一台机器上只能安装一个 XE 实例, 最大数据库大小为 12 GB,可使用的最大内存是 2G
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管理工具
heidisql
https://www.heidisql.com/download.php

快速导出数据库结构
SmartSQL
https://gitee.com/izhaofu/SmartSQL

错误提示：ERROR 1273 (HY000): Unknown collation: ‘utf8mb4_0900_ai_ci’
是因为linux下MySQL版本不兼容导致的
我们需要做的是打开我们导出的的sql文件

• 把文件中的所有的utf8mb4_0900_ai_ci替换为utf8_general_ci
• 以及utf8mb4替换为utf8

最后再重新导入成功。

ALTER USER ‘sqluser’@’%’ IDENTIFIED WITH mysql_native_password BY ‘sqluser’;
FLUSH PRIVILEGES;