mysql-connector-java本地试验
mysql-connector-java本地试验
题外话：因为Intellij配置报错java: 错误: 不支持发行版本 5，试过调整project structure也不行，所以直接在Ubuntu里搞
- 环境：Ubuntu 22.04
- 软件：MySQL 8.0.39, jdk17.0.12
编写数据库
CREATE DATABASE test_db;
USE test_db;
CREATE TABLE users(id INT PRIMARY KEY AUTO_INCREMENT,name VARCHAR(50),age INT
)
INSERT INTO users (name, age) VALUES ('Alice', 25), ('Bob', 30);
EXIT;
创建项目文件
mkdir ~/my-java-project && cd ~/my-java-project
vim编写Main.java
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;public class Main{public static void main(String[] args){String jdbcUrl = "jdbc:mysql://localhost:3306/test_db?useSSL=false&serverTimezone=UTC";String username = "root";String password = "密码"; //替换成MySQL密码Connection connection = null;Statement statement = null;try{connection = DriverManager.getConnection(jdbcUrl, username, password);statement = connection.createStatement();String sql = "SELECT * FROM users";ResultSet resultSet = statement.executeQuery(sql);while(resultSet.next()){System.out.println("ID:" + resultSet.getInt("id"));System.out.println("Name:" + resultSet.getString("name"));System.out.println("Age:" + resultSet.getInt("age"));}resultSet.close();}catch(Exception e){e.printStackTrace();}finally{try{if(statement != null) statement.close();if(connection !=null) connection.close();}catch(Exception e){e.printStackTrace();}}}
}
ESC :wq退出编辑
trouble shooting
- 官网下载MySQL对应驱动包
- 移动包到项目文件夹
- 这里官网下载的为".deb"包，需要安装，安装完成后所在目录一般为/usr/share/java/mysql-connector-java-x.x.x.jar,
- 没有对应的版本，所以我下载了9.0.0
cp /mnt/c/Users/用户名/Downloads/mysql-connector-j-9.0.0-1ubuntu22.04_all.deb ~/my-java-project/ //移动到项目文件夹
dpkg -i mysql-connector-j_9.0.0-1ubuntu22.04_all.deb //这里名字容易打错，注意下划线
- 编译与执行
javac -cp .:/usr/share/java/mysql-connector-java-x.x.x.jar Main.java
java -cp .:/usr/share/java/mysql-connector-java-x.x.x.jar Main
- 输出
ID:1
Name:Alice
Age:25
ID:2
Name:Bob
Age:30
- MySQL用户权限（若出现拒绝访问）
GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' WITH GRANT OPTION;
FLUSH PRIVILEGES;
EXIT;
参数解释
dbkg: 包管
|: 管操符
grep: 搜文，后接字段名
-f: apt-get选项，fix-broken，修复依赖关系
-cp: 指定路径，'.'指当前路径，':/usr/share/'指jar文件路径，这样做将类文件和jar加入jvm类路径。