JDBC-API详解-PreparedStatement

 

package Test;

import org.junit.Test;

import java.sql.*;

public class JDBCdemo6_PreparedStatement {
    /*
    *API详解：PreparedStatement
    * */
    @Test
    public void testUserLogin() throws Exception {
        //1.注册驱动
        //Class.forName("com.mysql.jdbc.Driver");
        //2.获取连接
        String url = "jdbc:mysql:///test?useSSL=false";
        String username = "root";
        String password = "1234";
        Connection conn = DriverManager.getConnection(url, username, password);

        //接收用户输入用户名和密码
        String name="zhangsan";
        String pwd="123";

        String Sql=" select * from tb_user where username=? and password=? ";//用英文问号

        //获取pstmt对象
        PreparedStatement pstmt = conn.prepareStatement(Sql);

        //设置？的值
        pstmt.setString(1,name);
        pstmt.setString(2,pwd);

        //执行sql
        ResultSet rs = pstmt.executeQuery();

        //判断登录是否成功
        if (rs.next()){
            System.out.println("登录成功");
        }else {
            System.out.println("登录失败");
        }

        //7.释放资源
        rs.close();
        pstmt.close();
        conn.close();
    }


}