show databases;
create database test;
use test;
show tables ;
create table test.score
(
id int null,
yuwen varchar(20) null
);
INSERT INTO test.score (yuwen) VALUES ('89');
INSERT INTO test.score (yuwen) VALUES ('63');
INSERT INTO test.score (yuwen) VALUES ('74');
select * from score;
describe score;
show columns from score;
drop table score;
drop database test;
delete from score;
truncate table score;
create user if not exists test identified by 'test';
alter user 'test'@'%' identified by '123456';
rename table score to score1;
alter table score add column shuxue varchar(20);
alter table score drop column shuxue;