数据库基础命令

• 访问数据库

/usr/bin/mysql -u root -p password

• 显示所有库名

show databases;

• 切换数据库

use database_name;

• 显示所有表名：

show tables;

• count查询

select count(1) from table_name where pid=111;

• 基础查询语句

select * from table_name where pid=2543425 order by id desc limit 0,10;

0表示偏移量，10表示查询size；

order by需要放在limit前面，否则会报类似mysql错误：

com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'order by id desc' at line 1