空白页面即将进行SQL提取

I am unable to get any output from the database. There are around 13000 entries in my database. However when I am trying to limit the result by 350 then the output is there but when i remove the limit then a blank page is coming. Also when i am fetching other columns then all 13000 queries are being returned.What to do now?

<?php

$servername = "localhost:3306";
$username = "root";
$password = "mypassword";
$database = "mydatabase";

$conn = new mysqli($servername, $username, $password, $database);

if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

$info = array(); 


$sql = "SELECT Customer_Name FROM enquiry ;";


$stmt = $conn->prepare($sql);


$stmt->execute();


$stmt->bind_result($Customer_Name);


while($stmt->fetch()){

array_push($info, $Customer_Name);
}




echo json_encode($info);
?>

you need to free up the result after process. try this format so that you can get error message too.

$execute=mysql_query($sql,$conn);
 if (!$execute) {
     die "Query ($sql) failed: " . mysql_error();
 }
 while ($row=mysql_fetch_assoc($execute)) {
    /* loop through a result set even if you don't think you need to. */
    print_r($row);
 }
 mysql_free_result($execute);

Also check for max_allowed_packet in SQL.