基本语句
sql语句要以;结尾,格式一般是
命令
from 表名
其中update不需要from
连接数据库
mysql
-u root
-p
创建数据库
create database mydb1;
切换数据库
use database mydb1;
删除数据库
drop database mydb1;
创建表
create table student1(id int,name varchar(30),age int)
插入数据 ##:
insert into student1(id,name,age) values(1,'AoBaMa',60);
或者:
insert into student1(name,age) values('AoBaMa2',60);
或者:
insert into student1 values(3,'AoBaMa3',60);
select:
select *
from student1;
select name
from student1;
where:
select * from student1 where id=1;
select * from student1 where name='AoBaMa';
distinct ##:
在列name中,去掉重复姓名后的数据
select distinct name from student1
and or
根据条件查询
select * from student1 where name='TeLangBu' and age=70;
select * from student1 where name='TeLangBu' or age=70;
order by
根据x排序
select * from student1 order by age;
update
更新数据,结合where使用
update student1 set name='LiBingBing' where id=3;
delete
删除表中的行
delete from student1 where name='AoBaMa';
删除所有数据
delete * from student1;
sql高级语句
通配符
通配符说明
%代表0个或多个字符_(下划线)代表一个字符[charlist]字符列中的任何单一字符[^charlist]或[!charlist]不在字符列中的任何单一字符
like
查询name列以g开始的数据
select * from websites where name like 'g%';
in
select * from websites where name in('google','facebook');
between
查询id在2和4之间的数据。[2,4]
select * from websites where id between 2 and 4;
查询区间[2,4]外的数据:
select * from websites where id not between 2 and 4;
其它
select limit
查询前2项
select * from webistes limit 2;
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