JDBC 01: 建立与数据库的连接

示例：

建立与数据库"web01"的连接, 并查询输出"user"表中所有的数据

package com.Jasper2003.jdbc01;

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

public class JDBCDemo01 {
    public static void main(String[] args) {
        
        Connection con = null;
        Statement stmt = null;
        ResultSet rs = null;
        
        try {
            Class.forName("com.mysql.jdbc.Driver"); // 使用什么驱动连接数据库
            
            String url = "jdbc:mysql://localhost:3306/web01?useUnicode=true&characterEncoding=UTF8&useSSL=false";
            String user = "root";
            String password = "root";
            
            con = DriverManager.getConnection(url,user,password); 
            stmt = con.createStatement();
            rs = stmt.executeQuery("select * from user");
            
            while(rs.next()) {
                // 获取数据的第一种方式: 列数
                System.out.println(rs.getInt(1)+","+rs.getString(2)+","+rs.getString(3));
                // 获取数据的第二种方式: 列名
                System.out.println(rs.getInt("id")+","+rs.getString("username")+","+rs.getString("password"));
            }    
            
        } catch (Exception e) {
            
            e.printStackTrace();
        } finally {
        
            try {
                if(rs!=null)
                    rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        
            try {
                if(stmt!=null)
                    stmt.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        
            try {
                if(con!=null)
                    con.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}

输出: