MYSQL语句回顾

建表语句:

create table pet(name varchar(20),owner varchar(20),species  varchar(20),sex char(1),birth date,death date); 

插入语句:

insert into pet values('puffball','Diane','hamster','f','1999-03-30',null);

查询语句:

select * from pet where sex='f' and birth > '1999-05-01'

更新语句:

update pet set name = 'ak47' where name='ajx'

或者连接:

select * from pet where species='dog' or species='cat'

计算年龄:

select name,birth,curdate(),
(year(curdate())-year(birth))-(right(curdate(),5)<right(birth,5)) as age
from pet;