Uploading and displaying image to mysql using html and php - php

Question

I'm trying to upload an image of my HTML form into my MySQL blob column. the insertion is done successfully but the display of the image does not work properly knowing that images inserted directly into MySQL are displayed correctly.
HTML code:
<form class="form-horizontal" method='POST' action="add_question_submit.php" id="addQuestionForm" enctype="multipart/form-data">
<div class="form-group">
<textarea rows="4" cols="50" name="question" form="addQuestionForm" placeholder="Enter Question in brief.... " required></textarea><br>
<input type="file" class="form-control" id="image" name="image" required><br>
<input type="text" class="form-control" id="answer" placeholder="Enter Correct Answer" name="answer" required><br>
<input type="number" class="form-control" id="category_id" placeholder="Enter category id (only numeric)" name="category_id" required><br>
<input type="number" class="form-control" id="level_id" placeholder="Enter level id (only numeric)" name="level_id" required><br>
<input type="submit" name="submit" value="submit" class="btn btn-primary">
</div>
</form>
PHP code:
$file_temp = base64_encode( file_get_contents( $_FILES['image']['tmp_name'] ) );
$image = getimagesize($file_temp);
$query = "INSERT INTO questions(question_name, image, answer, category_id,level_id)VALUES('$question', '$image','$answer', '$category_id', '$level_id')";
$result = mysqli_query($conn, $query);
header("Location: display_question.php");
display_question.php :
<td><?php echo '<img src="data:image/png;base64,'.base64_encode($row['image']).'" />'; ?></br><br/></td>

Answer 1

Below is the function which will upload the images to specific folder.
You can all below function like:
Param 1: is the folder where we need to store the new image
Param 2: is FILES
Param 3: if any prefix for the image we need to pass it.
Param 4: if there is any previously uploaded image for same record. It should be deleted from the folder. Generally it is usefull when you are editing particluar record.
uploadfile("profile",$_FILES,"profile_pic");
Code is here:
function uploadfile($folder,$data,$preFix = "logo_",$previousImage="") {
$location = (pathinfo($_SERVER['SCRIPT_FILENAME']));
$uploads_dir = $location['dirname'] . "/assets/uploads/" . $folder . "/";
$fileNames = "";
$tmp_name = $data["tmp_name"];
$name = $data["name"];
$fileExtension = pathinfo($name, PATHINFO_EXTENSION);
$newfilename = $preFix . date("ymdhms") . '.' . $fileExtension;
$fulldest = $uploads_dir . $newfilename;
if (move_uploaded_file($tmp_name, $fulldest)) {
if($previousImage != "")
$this->removePreviousImage($folder, $previousImage); //deleting existing image
return $newfilename;
} else {
exit("Error File Uploading");
}
}

Answer 2

First you are storing the wrong information onto the database, you are storing the file size and not the encoded image.
$file_temp = base64_encode( file_get_contents( $_FILES['image']['tmp_name'] ) );
$image_size = getimagesize($file_temp);
$query = "INSERT INTO questions(question_name, image, answer, category_id,level_id)
VALUES('$question', '$file_temp','$answer', '$category_id', '$level_id')";
$result = mysqli_query($conn, $query);
header("Location: display_question.php");
Second, if you have stored the base64 encoded version of the file onto the database you do not need encode it again when you retrieve it from the database so your <img> tag should be
<?php echo "<img src='data:image/png;base64,$row[image]'/>"?>
</br><br/></td>
And thirdly and most importantly you need to be using parameterise bound queries to protect your app from SQL Injection Attack
$file_temp = base64_encode( file_get_contents( $_FILES['image']['tmp_name'] ) );
$image_size = getimagesize($file_temp);
$query = "INSERT INTO questions
(question_name, image, answer, category_id,level_id)
VALUES(?,?,?,?,?)";
$stmt = $conn->prepare($query);
$stmt->bind_params('sssss', $question,
$file_temp,
$answer,
$category_id,
$level_id);
$result = $stmt->execute();
if (!$result) {
echo $conn->error;
}
header("Location: display_question.php");