为什么这些CSV记录重复？

Question

我遇到问题，在MYSQL数据库中记录重复三次可能是什么问题？任何想法？

HTML

    <form enctype="multipart/form-data" method="POST" action="" >
     CSV<input type="file" name="file" />
    <input type="submit" value="submit" name="submit"/>
    </form>

PHP

    <?php
    $connection = mysql_connect("_SERVER_","_USER_","_PASSWORD_")
    or die ("Couldn't connect to server");
    $db = mysql_select_db("_DATABASE_", $connection)
    or die ("Couldn't select database");
    if(isset($_POST['submit']))
    {
    $file = $_FILES['file']['tmp_name'];
    $handle = fopen($file,"r");

    while(($fileop = fgetcsv($handle,1000,",")) !== FALSE)
    {
    $a = $fileop[0];
    $b = $fileop[1];
    $c = $fileop[2];
    $d = $fileop[3];
    $e = $fileop[4];
    $f = $fileop[5];

    $sql = mysql_query("INSERT INTO f38uj_zhgooglemaps_markers (title, addresstext,  published, baloon, icontype, mapid) 
    values('$a', '$b', '$c', '$d', '$e', '$f')");

    }

    }

    ?>