executeQuery

package org.west.demo4;

import java.sql.*;

public class Test {
    public static void main(String[] args) {
        Connection connection=null;
        PreparedStatement ps=null;
        ResultSet resultSet=null;
        try {
            //加載類驅動
            Class.forName("com.mysql.jdbc.Driver");
            //建立連接
            connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/jdbcstudy", "root", "123456");

            String sql="select id,Sname,pwd from t_user where id>?";
            //通過connection 獲取prepareStatement對象對sql語句進行預編譯 防止sql注入
            ps = connection.prepareStatement(sql);
            //paramenterindex:1  表示第一個占位符所需要輸入的數值
            ps.setString(1,"2");
            //executeQuery()執行查找元素返回的結果集
            resultSet = ps.executeQuery();
            while(resultSet.next()){
                //columnindex 表示的是數據庫的第一列的需要查詢的那個列的屬性的信息  比如 id
                System.out.println(resultSet.getString(1));
                //Sname
                System.out.println(resultSet.getString(2));
                //pwd
               System.out.println(resultSet.getString(3));
            }

        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        catch (SQLException e) {
            e.printStackTrace();
        }finally{
            if(connection!=null){
                try {
                    connection.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if(ps!=null){
                try {
                    ps.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if(resultSet!=null){
                try {
                    resultSet.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }

        }
    }
}