jdbc連結資料庫

   1.使用Statement，建立Statement物件，但是這種不安全，可以通過在資料庫密碼中新增or語句來使登入強行成功。

/*
 * 有點不安全的一種
 * */
package com.exp2;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;

public class Test1 {
    public static void main(String[] args) throws Exception {
        Class.forName("com.mysql.jdbc.Driver");

        String url = "jdbc:mysql://10.21.1.10:3306/oracle?useUnicode=true&characterEncoding=UTF-8";
        String user = "root";
        String pwd = "zhang";

        Connection conn = DriverManager.getConnection(url, user, pwd);

        Statement stmt = conn.createStatement();

        String sql = "select * from user";
        ResultSet rs = stmt.executeQuery(sql);

        List<User> list = new ArrayList<User>();
        while(rs.next()){
            int id = rs.getInt("id");
            String name = rs.getString("name");
            int age = rs.getInt("age");
            String money = rs.getString("money");
            String dept = rs.getString("dept");
            User u = new User(id, name, age, money, dept);
            list.add(u);
        }

        System.out.println(list);
    }
}
 

2.使用PreparedStatement，建立PreparedStatement物件，但是這種相對安全，必須通過正確的賬號密碼操作。

/*
 * 另一種
 * */

package com.exp1;

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

public class Test {
    public static void main(String[] args) throws ClassNotFoundException, SQLException {

        Class.forName("com.mysql.jdbc.Driver");

        String url = "jdbc:mysql://10.21.1.10:3306/oracle?useUnicode=true&characterEncoding=UTF-8";
        String user = "root";
        String pwd = "zhang";

        Connection conn = DriverManager.getConnection(url, user, pwd);

        String sql = "select *from student where score > ? and age < ?";

        PreparedStatement ps = conn.prepareStatement(sql);
        ps.setDouble(1, 60);
        ps.setInt(2, 20);


        ResultSet rs = ps.executeQuery();

        while(rs.next()){
            System.out.println(rs.getString("name")+"---"+rs.getInt("age")+"---"+rs.getDouble("score"));
        }

        rs.close();
        ps.close();
        conn.close();
    }
}
 

可能寫的不是太好，希望看到的大佬給點建議，萌新對比採納。