SQL语句复习

CREATE table user(name varchar(20),age int);INSERT INTU user values('guojinpeng',18),('lisi',19);SELECT * FROM jsp_db.user;UPDATE user set name='guo' where name='guojinpeng';SELECT * FROM jsp_db.user;DELETE from user where name='lisi';SELECT * FROM jsp_db.user;ALTER table user add email varchar(50);SELECT * FROM jsp_db.user;UPDATE user set email='[e-mail]' where name='guo';SELECT * FROM jsp_db.user;ALTER table user rename T_user;SELECT * FROM jsp_db.T_user;ALTER table T_user drop email;SELECT * FROM jsp_db.T_user;ALTER table T_user change name username varchar(20);SELECT * FROM jsp_db.T_user;ALTER table T_user change username username char(10);SELECT * FROM jsp_db.T_user;