sql操作语句记录
-- ddl
create database test;
show databases;
create database if not exists test;
create database test character set utf8;
show create database test;
alert database test default character set gbk;
drop database test;
select database();
use test;
create table student(id int,name varchar(10),age int,birthday date,sex char(1));
show tables;
desc student;
show create table student;
create table student1 like student;
drop table student1;
drop table if exists student1;
alter table student add remark varchar(20);
alter table student modify remark varchar(100);
alter table student change remark intro varchar(20);
alter table student drop remark;
rename table student to student2;
alter table student character set gbk;
-- dml
insert into student (id,name,age)values(1,"test",12);
select * from student;
insert into student values(2,"ivan",12);
insert into student1 select * from student;
insert into student1(id,name,sex) select id,name,sex from student;
update student1 set sex='女';
update student set sex='男' where id=2;
delete from student where id=3;
delete from student;
truncate table student;
select * from student;
select age from student;
select name as 姓名,age as 年龄,sex as 性别 from student;
select distinct name,age from student;
select match+english 总成绩 from student;
select name 姓名,age+10 as 年龄 from student;
