在if结构中使用mysqli_query [关闭]

Question

I have a basic question, just starting to dive into PHP and Mysql.

There seems to be an error in this construct, can anyone help me?

Thanks! K.

if ($password = mysqli_query ("SELECT password FROM users WHERE firstname = '$username'")) {

    echo "password success!";

     }
         else {
          echo "Password fail!";
}

Answer 1

In mysqli you have to store your db_connection into a variable and have to pass in every query. Below is the complete path what you have to follow:

1. Create connection with database by using host_name, user_name, password,db_name. And store connection into a variable.
2. You can run any query by passing connection variable.

below code is:

<?php

$con = mysqli_connect("localhost","my_user","my_password","my_db");

// Check connection
if (mysqli_connect_errno())
{
    echo "Failed to connect to MySQL: " . mysqli_connect_error();
}

if ($password = mysqli_query ($con, "SELECT password FROM users WHERE firstname = '$username'")) {
    echo "password success!";
}
else {
    echo "Password fail!";
}
?>