【MySQL】增删改查

下面在ubuntu下连接mysql

命令行连接：mysql -uroot -p->密码
退出：exit

1 数据库
查看：show databases;(分号一定要加！！！)
创建（增）：create database python04 charset=utf8;(设置中文)
显示：show create database python04;
删除（删）：drop database python04;

选择
use python04;
select database();

2 数据表
查看：show tables;
删除（删）：drop table ~;
创建（增）：create table xxxx(id int,name varchar(30));
create table yyyy(id int unsigned not null auto_increment primary key,
name varchar(30));
create table students(age tinyint(3) unsigned default ‘0’,
birth date default ‘2000-01-01’,
gender enum(‘男’,‘女’,‘中性’,‘保密’) default ‘保密’,
cls_id int(10) unsigned default null);
查看表结构：
desc xxxx;或show create table xxxx；
desc yyyy;

desc students;(windows下显示不完整，因此利用linux系统下显示)

增删改查（重点：主要针对数据表而言）

改
a 修改表结构
1加字段 alter table students add id int not null auto_increment primary key,name varchar(30);
alter table students add high decimal(5,2);

2修改字段（不重命名）
alter table students modify birthday date;
3修改字段（重命名）
alter table students change birthday birth date dafault “2000-01-01”;

b 改某个属性具体值
update students set gender=1 where id=3;

删
1 删除某个属性(整列)
alter table students drop high;

2 删除某个值对应的所有属性(整行)
delete from students where name=“小刘”;

增
插入值：insert into students values(18,“2009-01-01”,“男”,0,0,“老王”,188.88);
select * from students;

部分插入行：insert into students (name,gender) values (“小乔”，2)；
select name as “姓名”,gender as “性别” from students;（加as增强可读性！）

建立完整表格如下：

查（查看表具体数据）
select * from students where id>6;或where name=“小刘”;

附作者相关研究：
***Python:***
Python实现线性回归、逻辑回归、KNN、SVM、朴素贝叶斯、决策树、K-Means7种机器学习算法的经典案例——亲测可用，链接
https://download.youkuaiyun.com/download/qq_35778860/20715889
Python实现飞机大战的完整代码——亲测可用，链接
https://download.youkuaiyun.com/download/qq_35778860/57165535
Python爬虫获取豆瓣网评分Top200的电影——亲测可用，链接
https://download.youkuaiyun.com/download/qq_35778860/56379309
Python根据下拉选项绘制雷达图和柱形图（异常预控平台）——亲测可用，链接
https://download.youkuaiyun.com/download/qq_35778860/20715210
Python根据下拉选项绘制雷达图和柱形图（异常预控平台）——亲测可用，链接
https://download.youkuaiyun.com/download/qq_35778860/20715210
python实现雷达图——亲测可用，链接
https://download.youkuaiyun.com/download/qq_35778860/20695215
基于python的北京房屋出租数据可视化分析与3D展示——亲测可用，链接
https://download.youkuaiyun.com/download/qq_35778860/20675051
基于Python设计的web接口聊天机器人
https://download.youkuaiyun.com/download/qq_35778860/66662593
用Python进行自然语言处理（中文）.rar
https://download.youkuaiyun.com/download/qq_35778860/63652414
《机器学习实战》全书python代码——很全很完整
https://download.youkuaiyun.com/download/qq_35778860/62203534
Python3实现十大排序算法
https://download.youkuaiyun.com/download/qq_35778860/61630851
***C#***
成绩管理系统(C/S结构的应用系统，含access数据库)——C#实现
https://download.youkuaiyun.com/download/qq_35778860/66967387
C#实现学生信息管理系统（包括增删改查功能）——亲测可用
https://download.youkuaiyun.com/download/qq_35778860/61620149
***Matlab***
极限学习机ELM+OSELM+KELM+半监督SSELM+USELM的matlab程序(附完整代码)
https://download.youkuaiyun.com/download/qq_35778860/56378533
P+近邻KNN+LS最小二乘算法的matlab代码——亲测可用（含实例）
https://download.youkuaiyun.com/download/qq_35778860/56378309
基于matlab的卷积神经网络实现手写数字识别
https://download.youkuaiyun.com/download/qq_35778860/66667747
基于MATLAB的人工蜂群算法
https://download.youkuaiyun.com/download/qq_35778860/66665944
利用MATLABsilulink搭建有源电力滤波器仿真.zip
https://download.youkuaiyun.com/download/qq_35778860/63659150
动态规划MATLAB程序.zip
https://download.youkuaiyun.com/download/qq_35778860/63658838
基于matlab的模式识别基础实例源代码.zip
https://download.youkuaiyun.com/download/qq_35778860/63658486
Matlab_动态窗口法实现机器人在障碍环境下的模拟避碰仿真.zip
https://download.youkuaiyun.com/download/qq_35778860/63658232
bp神经网络整定pid参数matlab应用程序.rar
https://download.youkuaiyun.com/download/qq_35778860/63656174
利用深度学习的matlab程序编码仿真实现图像分割.zip
https://download.youkuaiyun.com/download/qq_35778860/63655267
***Java***
基于java的信息管理系统
https://download.youkuaiyun.com/download/qq_35778860/66658535
Java swing学生成绩系统（源码+数据库脚本）.rar
https://download.youkuaiyun.com/download/qq_35778860/63653951
***Jsp***
jsp学生信息管理系统（源码+数据库脚本）.zip
https://download.youkuaiyun.com/download/qq_35778860/63653655
***SCN***
随机配置网络SCN实现的matlab代码——亲测可用
https://download.youkuaiyun.com/download/qq_35778860/61636684
***BLS***
宽度学习BLS的matlab代码+Mnist数据集
https://download.youkuaiyun.com/download/qq_35778860/61635045
***Mysql***
Mysql增删改查代码操作，很全很完整——亲测可用
https://download.youkuaiyun.com/download/qq_35778860/61626574
***C***
基于单片机的交通灯控制系统设计（含代码，原理图）——C语言实现
https://download.youkuaiyun.com/download/qq_35778860/60383113
基于单片机的温度控制系统设计代码（含代码，原理图）——C语言实现
https://download.youkuaiyun.com/download/qq_35778860/60379923
郭天祥51单片机书中400例程——亲测可用
https://download.youkuaiyun.com/download/qq_35778860/58014293
***其他***
微信转盘抽奖小程序源码.rar
https://download.youkuaiyun.com/download/qq_35778860/63652890