尝试通过 php 将照片上传到 myphpadmin 但失败

Question

So I am just learning PHP and I have the below code but it does not send my photos to my database. My database file works as I use if for other pages and the data gets sent to the database. My code is basic as this is how I know how to write it at the moment but there is something I am missing. The action page comes back blank. Not even one error mentioned and the photo does not show in the database table that they are supposed to go. Any advice would be apperciated. Again just learning so I know my code is basic.

//Form
                    
<form enctype="multipart/form-data" action="Upload.php" method="post">
<input type="file" name="photo" id="fileSelect">
<textarea align="center" name="Hashtag" cols="40" placeholder ="Describe your photo"></textarea>
<input value="Upload" class="special big" type="submit">
</form>


//Action file Upload.php

<?php
require "DB.PHP";

if (isset($_POST["submit"]))
{
$tag = $_POST["Hashtag"];
$photo = rand(1000,10000)."-".$_FILES["photo"]["name"]; //Create unique file name

$sql = "INSERT INTO photos (hashtag,Image) VALUES('$tag','$photo')";
if ($conn ->query ($sql)){
echo '<script type="text/javascript">';
echo 'alert("Your Photo was submitted.")';  
echo '</script>';
echo "<script>setTimeout(\"location.href = 'Photo_Submit.php';\",0000);</script>";
   }

else "Error: ".$sql. "<br>". $conn->error;     
$conn->close();
}
?>

//table in database

 `Image` varchar(255) NOT NULL,
  `hashtag` varchar(255) NOT NULL,
  `user_id` varchar(50) CHARACTER SET utf8 NOT NULL,
  `Time Stamp` int(11) NOT NULL DEFAULT current_timestamp(),
  PRIMARY KEY (`user_id`)

Answer 1

1. I don't know if it is a mistake when typing the question but I can see that in your else you are not echoing the error. Place echo before the error

if () {
    //
} else {
    echo "Error: ".$sql. "<br>". $conn->error;
}

2. Per your table definition, user_id is NOT NULL means the user_id field cannot be null. It has to be set on every request unless you set a default value (like for the timestamp)!

3. Consider the advice about Dharman on SQL injections and others.

Answer 2

Use longtext for your image in your database, not varchar(255)