数据库Mysql 操作
和数据库相关:
1.创建数据库 create database db1;
create database db1 character set gbk
2.查看所有库: show databases;
3.查看单独的库: show create database db1;
4.删除数据库: drop database db1;
5.使用数据库:use db1;
和表相关:
1. 创建表
create table t1 (id int,
name varchar(10));
-制定引擎和字符集
create table t1 (id int,
name varchar(10)) engine=innodb charset=utf8;
2.查看所有表 show tables;
3.查看表结构 desc t1;
4.查看表属性 show create table t1;
对表操作
1.创建表 create table student (id int,name varchar(10));
2.带引擎和字符集的创建 create table student (id int,name varchar(10)) engine=innodb(myisam) charset=gbk;
3.查看所有 show tables;
4.查看表属性 show create table student;
5.查看表结构 desc student;
和表相关sql:
1.创建表:create table t1 (id int) engine=innodb charset=utf8;
2.查看所有: show tables;
3.查看单个:desc t1; show create table t1;
4.修改表名: rename table t1 to t2;
5.添加字段: alter table t2 add age int (添加到最后面);
alter table t2 add age int first (添加到最前面)
alter tabke stue add age int after id;(某个字段后面添加)
6.修改名和类型:alter table t2 change age fatherAge int;
7.修改类型和顺序:alter table t2 modify fatherAge varchar(20) (first或after 字段名);
8.修改属性:alter table t2 engine=myisam charset=utf8;
8.删除字段:alter table t2 drop age;
9.删除表: drop table t2;
数据相关SQL
1.插入数据:
insert into t1 values(2,'lisi',2,3);
insert into t1 values(3,'wangwu',2,3);
insert into t1 values(4,'zhaoliu',2,3);
insert into student (id,name) values (1,'xm');
批量就是在values后面写多个小括号 通过, 分开 括号里面写值
2.查询数据:select * from student;
select id,name from student;
3.修改数据: update student set age=18 where age=20;
4.删除:delete from student where age=18;
查看
select title from t_item;
select title from where category='riyongping';
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