?Linux中nano和vim讀可以打開記事文件。

ifdown ens33

ifup ens33

關閉，開啟網絡

rm -r lesson1

gcc -o code1 code1.c

?編譯c語言代碼

./code1

執行c語言代碼?

rm -r dir

刪除文件夾?

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

展示數據庫

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

使用test數據庫，使用tb_user表。

mysql> desc tb_user;

查看表結構。

?

課設中遇到的問題：

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

【異常】JDK21報錯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