mysql数据库连接代码怎么讲

import mysql.connector

# 创建数据库连接
cnx = mysql.connector.connect(
  host="localhost",
  user="your_username",
  password="your_password",
  database="your_database"
)

# 创建游标对象
cursor = cnx.cursor()

# 执行SQL查询
query = "SELECT * FROM your_table"
cursor.execute(query)

# 获取查询结果
result = cursor.fetchall()

# 打印查询结果
for row in result:
  print(row)

# 关闭游标和连接
cursor.close()
cnx.close()

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class MySQLConnector {

  public static void main(String[] args) {
    Connection conn = null;
    Statement stmt = null;
    ResultSet rs = null;
    
    try {
      // 加载MySQL驱动
      Class.forName("com.mysql.cj.jdbc.Driver");
      
      // 创建数据库连接
      conn = DriverManager.getConnection(
        "jdbc:mysql://localhost:3306/your_database",
        "your_username", "your_password");
      
      // 创建Statement对象
      stmt = conn.createStatement();
      
      // 执行SQL查询
      String query = "SELECT * FROM your_table";
      rs = stmt.executeQuery(query);
      
      // 处理查询结果
      while (rs.next()) {
        // 获取每一行数据
        String column1 = rs.getString("column1");
        String column2 = rs.getString("column2");
        System.out.println(column1 + " - " + column2);
      }
    } catch (ClassNotFoundException | SQLException e) {
      e.printStackTrace();
    } finally {
      // 关闭ResultSet、Statement和Connection
      if (rs != null) {
        try {
          rs.close();
        } catch (SQLException e) {
          e.printStackTrace();
        }
      }
      if (stmt != null) {
        try {
          stmt.close();
        } catch (SQLException e) {
          e.printStackTrace();
        }
      }
      if (conn != null) {
        try {
          conn.close();
        } catch (SQLException e) {
          e.printStackTrace();
        }
      }
    }
  }
}