I have a script with the code below that inserts a .csv file into a table, and had an issue where if no file is selected, it throws "fgetcsv() expects parameter 1 to be resource, boolean given" about 1,000,000 times or so until it fills up the table, the error log, and eventually the server hard drive. I'm guessing someone probably has a simple solution on the below code on how to prevent that going forward, but I've just spent some time looking into it and haven't been able to find the solution.
<?php
$conn = mysql_connect("localhost", "dbuser", "dbpassword") or die(mysql_error());
mysql_select_db("database") or die(mysql_error());
// Delete existing values in test table before inserting updated file
$sql_ini = "TRUNCATE table";
mysql_query($sql_ini) or die(mysql_error());
if(isset($_POST['SUBMIT']))
{
$file = $_FILES['file']['tmp_name'];
$handle = fopen($file,"r");
while(($fileop = fgetcsv($handle,1000,",")) != false)
{
$field1 = $fileop[0];
$field2 = $fileop[1];
$field3 = $fileop[2];
// check for default values and delete locked row before inserting data
if (!empty($field1))
{
// Insert .csv file into database
$sql = "INSERT INTO table (field1, field2, field3) values ('$field1', '$field2', '$field3')";
mysql_query($sql) or die(mysql_error());
}
}
if($sql)
{
// Show whether or not the file was added successfully:
echo "CSV file successfully imported.";
} else {
echo "Data Insert Failed";
}
}
}
?>
<form method="post" action="<?php echo $_SERVER['PHP_SELF'];?>" enctype="multipart/form-data">
<input type="file" name="file" />
<br>
<br>
<input type="submit" name="SUBMIT" value="Submit" />
</form>
Thank you in advance for your assistance, and I appreciate your help. 
