1. mysql启动

mysqld --console

2. mysql关闭

mysqladmin shutdown -uroot -proot

3. 免安装mysql配置：

启动mysql： mysqld --skip-grant-tables(跳过安全校验)， 修改mysql.user表里面的数据，最后flush privileges;

mysql  jdbc连接代码

1 Class.forName("com.mysql.jdbc.Driver");2

3 Connection connection = null;4 PreparedStatement preparedStatement = null;5 ResultSet resultSet = null;6

7 connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/mysql", "root", "root");8 preparedStatement = connection.prepareStatement("select host, user, password from user");

4. tomcat jdbc数据源JNDI配置

1

2

3 driverClassName="com.mysql.jdbc.Driver"url="jdbc:mysql://localhost:3306/mysql"username="root"password="root"

4 maxActive="30"maxIdle="30"maxWait="10000" />

5

5. mysql导出:

mysqldump -uroot -proot --max_allowed_packet=1048576 --net_buffer_length=16384 --extended-insert=FALSE --default-character-set=utf8 --routines --events "g2mdb" >export2.sql

6. mysql权限赋予

>grant all privileges on *.* to 'root'@'%‘ identified by 'root';

>flush privileges;

6. update join多表更新

update nms_res_device A

inner join (select ifnull(max(severity), 0) maxLevel, deviceId from nms_alm_info where clearTime = '0000-00-00 00:00:00' and isClear != 2 group by deviceId) TEMP

on A.deviceId = TEMP.deviceId

set A.alarmLevel = TEMP.maxLevel;