HTTPエラー500 mysql php？

Question

いくつかのデータを挿入しようとしましたが、HTTPエラー500が表示されません。理由はわかりません.txtファイルから複数の行を挿入しようとしました。

$conn = new mysqli("localhost", "***", "****", "***"); 
// Check connection 
if ($conn->connect_error) { 
die("Connection failed: " . $conn->connect_error); 
} 

    $contents = file_get_contents("cars.txt"); 
    $pollfields = explode(',', $contents); 

    $query = "INSERT INTO table (`name`) VALUES (?)"; 

    $zz = $mysqli->prepare($query); 

    $zz ->bind_param("s", $bb); 

    $mysqli->query("START TRANSACTION"); 
    foreach ($pollfields as $bb) { 
     $zz->execute(); 
    } 
    $zz->close(); 
    $mysqli->query("COMMIT"); 

Answer 1

私は

$conn = new mysqli("localhost", "***", "****", "***"); 
// Check connection 
if ($conn->connect_error) { 
die("Connection failed: " . $conn->connect_error); 
} 

    $contents = file_get_contents("cars.txt"); 
    $pollfields = explode(',', $contents); 

    $query = "INSERT INTO table (`name`) VALUES (?)"; 

    $zz = $conn->prepare($query); 

    $zz ->bind_param("s", $bb); 

    $conn->query("START TRANSACTION"); 
    foreach ($pollfields as $bb) { 
     $zz->execute(); 
    } 
    $zz->close(); 
    $mysqli->query("COMMIT");