1、查询数据：select * from xxx;例子：（1）select id,username,password from t_user;（2）select id,username,password,gender from t_user where gender = '男';（3）select id,username,password,gender from t_user where gender is null;
2、添加数据：insert xxx(id, username拘七呷憎) values(xx, "xxx");例子：insert into t_user(id, userna罪焐芡拂me) values(10, "hehehe");insert into t_user(id, gender, username, age, password) values(15, '男', 'shihu', 18, '123456');insert into t_user values(16, 'benladeng', '123456', '拉登', 'nan', 18);
3、修改数据：update tablename set xx=xx,xxx=xx where xxx=xxx and xxx=xxx;
4、删除数据：delete from tablename where xx=xxx and xxx = xxx or xxx = xxx;
5、DQL数据查询语言连接查询 左外连接 select e.name ename, e.gender, d.name dname from t_employee e left outer join t_department d on e.depart_id = d.id
6、设置数据库可以被其他计算机连接 打开名为mysql的数据库 --> user表 --> 将root的host改为% --> 提交 --> 重启mysql服务即可。
