sql语句查询数据库案例

package com.hanqi.test;

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

import com.hanqi.util.JdbcConnectionUtil;

public class Test {
    
    private static Connection con; //链接数据库
    private static PreparedStatement pste;// 执行sql语句
    private static ResultSet rs; //执行返回结果
    
    public static void main(String[] args) {
        init();
        String sql = "select * from appuser";
        try {
            pste = con.prepareStatement(sql);// 执行sql语句
            rs = pste.executeQuery();//执行完的返回结果
            
            while(rs.next()) {
                System.out.println(rs.getInt("id"));
                System.out.println(rs.getString("username"));
                System.out.println(rs.getString("password"));
                System.out.println(rs.getString("realname"));
                System.out.println(rs.getDate("createtime"));
                System.out.println("================================");
            }
            
        } catch (SQLException e) {
            e.printStackTrace();
        }
        close();
    }
    
    public static void init() {
        con = JdbcConnectionUtil.getConnection();
    }
    
    public static void close() {
        JdbcConnectionUtil.destroy(con,pste,rs);
    }
}