linux和mysql基础指令

 Linux中nano和vim读可以打开记事文件。

ifdown ens33

ifup ens33

关闭，开启网络

rm -r lesson1

gcc -o code1 code1.c

 编译c语言代码

./code1

执行c语言代码 

rm -r dir

删除文件夹 

mysql> show databases
    -> ^C
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| online_edu         |
| performance_schema |
| sys                |
| test               |
+--------------------+
6 rows in set (0.08 sec)

展示数据库

mysql> use test;
Database changed
mysql> create table tb_user(
    -> id int comment'编号',
    -> name varchar(50) comment'姓名',
    -> age int comment'年龄',
    -> gender varchar(1) comment'性别'
    -> );

使用test数据库，使用tb_user表。

mysql> desc tb_user;

查看表结构。

课设中遇到的问题：

【异常】JDK21报错NoSuchFieldError: Class com.sun.tools.javac.tree.JCTree$JCImport does not have member fie

【异常】JDK21报错NoSuchFieldError: Class com.sun.tools.javac.tree.JCTree$JCImport does not have member fie_java: java.lang.nosuchfielderror: class com.sun.to-CSDN博客https://blog.csdn.net/G971005287W/article/details/133350154