SQL语句

xiaoxiao2021-02-28  167

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;//获取全部数据 select name from student1;//获取name列的数据

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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