adding image to database html form - php

Question

I am trying to add records into a database. Each record has a corresponding image. The records are getting inserted into the database but it is not working for the image. I am getting this error "connected successfully Notice: Undefined variable: sql in C:\xampp\htdocs\Syokimaufc\addplayer.php on line 35 Error: Query was empty" How can i solve this?
<form action="addplayer.php"method ="post" enctype="multipart/form- data">
<p> id: <input type="text" name="playerid"/></p>
<p> Name: <input type="text" name="name"/></p>
<p> Age: <input type="text" name="age"/></p>
<p> Position: <input type="text" name="position"/></p>
<p> Nationality: <input type="text" name="nationality"/></p>
<p> Photo: <input type="file" name="image"/></p>
<input type="submit" value="submit"/>
<form/>
<?php
require 'connection.php';
$id = filter_input(INPUT_POST, 'playerid');
$name = filter_input(INPUT_POST, 'name');
$age = filter_input(INPUT_POST, 'age');
$position = filter_input(INPUT_POST, 'position');
$nationality = filter_input(INPUT_POST, 'nationality');
$_id = mysql_real_escape_string( $id );
$_name = mysql_real_escape_string( $name );
$_age = mysql_real_escape_string( $age );
$_position = mysql_real_escape_string( $position );
$_nationality = mysql_real_escape_string( $nationality );
if (isset($_POST['submit']))
{
$imageName = mysql_real_escape_string($_FILES ["image"]["name"]);
$imageData = mysql_real_escape(file_get_contents($_FILES["image"]["tmp_name"]));
$imageType = mysql_real_escape_string($_FILES["image"]["name"]);
if (substr($imageType,0,5) == "image")
{
$sql = "INSERT INTO players ( playerid, name, age, position, nationality, iname, image ) VALUES ( '$_id', '$_name', '$_age', '$_position', '$_nationality', '$imageName', '$imageData' )";
}
else
{
echo "only images are allowed";
}
}
if (!mysql_query($sql)){
die('Error: ' . mysql_error());
}

Answer 1

Put:
if (!mysql_query($sql)){
die('Error: ' . mysql_error());
}
Immediately after
$sql = "INSERT IN..."
The problem is that because you run the query outside of all your if checks, the query will be run even when there is no input data (eg: no form was submitted), and $sql will be non-existent in that case. Hence the "Undefined variable: sql" and the "Query was empty" errors