java连接MySQL数据库（jdbc）

Posted 2022-10-13 peng-zhao

package zp.itcase.JDBCdemo;

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

public class JDBCDemo3 
    public static void main(String[] args) 
        Statement stmt = null;
        Connection conn = null;
        try 
            // 1.注册驱动
            Class.forName("com.mysql.jdbc.Driver");
            // 2.获取连接对象
            conn = DriverManager.getConnection("jdbc:mysql:///db3", "root", "root");
            // 3. 定义sql
            String sql = "update account set balance = 1500 where id =3";
            // 4.获取执行sql的对象
            stmt = conn.createStatement();
            // 5.执行sql
            int count = stmt.executeUpdate(sql);
            // 6.处理结果
            if (count > 0) 
                System.out.println("修改成功");
             else 
                System.out.println("修改失败");
            


         catch (ClassNotFoundException e) 
            e.printStackTrace();
         catch (SQLException e) 
            e.printStackTrace();
         finally 
            if (stmt != null) 
                try 
                    stmt.close();
                 catch (SQLException e) 
                    e.printStackTrace();
                
            
            if (conn != null) 
                try 
                    conn.close();
                 catch (SQLException e) 
                    e.printStackTrace();