linux如何连接到mysql数据库

import pymysql

# 建立数据库连接
conn = pymysql.connect(host='主机名', port=端口号, user='用户名', password='密码', database='数据库名')

# 创建游标对象
cursor = conn.cursor()

# 执行SQL查询
sql = "SELECT * FROM 表名"
cursor.execute(sql)

# 获取查询结果
result = cursor.fetchall()
for row in result:
    print(row)

# 关闭游标和连接
cursor.close()
conn.close()

import java.sql.*;

public class MySQLConnector {
    public static void main(String[] args) {
        Connection conn = null;
        Statement stmt = null;
        ResultSet rs = null;

        try {
            // 加载数据库驱动
            Class.forName("com.mysql.cj.jdbc.Driver");

            // 建立数据库连接
            String url = "jdbc:mysql://主机名:端口号/数据库名";
            String user = "用户名";
            String password = "密码";
            conn = DriverManager.getConnection(url, user, password);

            // 创建Statement对象
            stmt = conn.createStatement();

            // 执行SQL查询
            String sql = "SELECT * FROM 表名";
            rs = stmt.executeQuery(sql);

            // 处理查询结果
            while (rs.next()) {
                // 处理每一行数据
                // 示例：String column1 = rs.getString("列名");
                // 示例：int column2 = rs.getInt("列名");
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            // 关闭ResultSet、Statement和Connection
            try {
                if (rs != null) {
                    rs.close();
                }
                if (stmt != null) {
                    stmt.close();
                }
                if (conn != null) {
                    conn.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}