• 注意，所有有关mysql测试都在cmd中实现的。
    • 打开cmd快捷键：win+r;输入cmd.
      • C:\Users\虚无>mysql -u root -p//输入要打开的数据库，但在此之前要配置环境
      • Enter password: **// 密码在PHP中查看
      • Welcome to the MySQL monitor. Commands end with ; or \g.
      • Your MySQL connection id is 18
      • Server version: 5.7.26 MySQL Community Server (GPL)
      • Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
      • Oracle is a registered trademark of Oracle Corporation and/or its
      • affiliates. Other names may be trademarks of their respective
      • owners.
      • Type ‘help;’ or ‘\h’ for help. Type ‘\c’ to clear the current input statement.
      • image.png
    • Microsoft Windows [版本 10.0.18363.1198]
    • (c) 2019 Microsoft Corporation。保留所有权利。
    • C:\Users\虚无>mysql -u root -p//输入数据库打开
    • Enter password: **//密码
    • Welcome to the MySQL monitor. Commands end with ; or \g.
    • Your MySQL connection id is 21
    • Server version: 5.7.26 MySQL Community Server (GPL)
    • Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
    • Oracle is a registered trademark of Oracle Corporation and/or its
    • affiliates. Other names may be trademarks of their respective
    • owners.
    • Type ‘help;’ or ‘\h’ for help. Type ‘\c’ to clear the current input statement.
    • mysql> create database guo;//创建一个guo的数据库
    • Query OK, 1 row affected (0.00 sec)
    • mysql> use guo;//使用刚创建好的数据库
    • Database changed
    • mysql> create table student1;//在guo的里面创建一个表格student1
    • ERROR 1113 (42000): A table must have at least 1 column//error是错误提示，如果没有错误则可能断开连接，重新输入
    • mysql> create table student1(//建立一个表格
    • -> id int,//输入int形变量
    • -> name varchar(20),相当于c语言中的char
    • -> age int,
    • -> sex varchar(5)
    • -> )engine myisam charset utf8;结束标志语句
    • Query OK, 0 rows affected (0.02 sec)//当出现这个语句则创建成功
    • 以下是输入信息格式，新输入的信息默认往下排
    • mysql> insert into student1(id,name,age,sex) values//一定要注意单词拼写！！！！
    • 如果重新打开cmd然后输入数据，要先打开root，然后guo数据库再输入insert…….
    • -> (1,’汪科’,19,’男’);
    • Query OK, 1 row affected (0.00 sec)
    • mysql> alter table student1 change sex 性别 varchar(5) default ‘男’;
    • Query OK, 0 rows affected (0.01 sec)
    • Records: 0 Duplicates: 0 Warnings: 0