How to retrieve an id after details are submitted - php

Question

I am having trouble with a major flaw with my database design. Below is my four tables:
Session Table:
SessionId SessionName
3 EROEW
Question Table:
QuestionId(PK) QuestionNo QuestionContent SessionId (FK)
11 1 Question1 3
12 2 Question2 3
13 3 Question3 3
Image_Question:
ImageQuestionId (PK) ImageId (FK) SessionId (Fk) QuestionNo (FK)
1 1 3 1
2 2 3 2
Image:
ImageId (PK) SessionId (Fk) QuestionNo (FK)
1 3 1
2 3 2
Now as you can see in the Image_Question Table, the QuestionNo refers to a QuestionNo which is non-unique or in other words a non unique field. Now I head this is bad practice.
Now I know you are going to say why not use QuestionId. Well the problem is that I can't use QuestionId because the images are uploaded to each question before a question is submitted and the only way we can give a question its own QuestionId is after the user has submitted the questions.
So what I tried to do was determine which question an uploaded image belongs to by getting the QuestionNo from the page as well as the SessionId.
Now as I have heard this is a bad way of doing it, I want to change QuestionNo (FK) in Image_Question to QuestionId (FK). But I am not going to be able to upload files and insert details of the uplaod after questions are submitted to get the QuestionId, to me that can't be done.
So my question is that is there a way we can some how store each uploaded image into a temp table, get the question number and sessionid for each image belongs to and then from there be able to find the QuestionId and store the QuestionId value in the Image_Question Table?
Below is my current php code where it inserts the values after image is uploaded:
Be very greatful if somebody can update code below but any answer will be helpful:
move_uploaded_file($_FILES["fileImage"]["tmp_name"],
"ImageFiles/" . $_FILES["fileImage"]["name"]);
$result = 1;
$imagesql = "INSERT INTO Image (ImageFile)
VALUES (?)";
//Dont pass data directly to bind_param store it in a variable
$insert->bind_param("s",$img);
//Assign the variable
$img = 'ImageFiles/'.$_FILES['fileImage']['name']; //GET THE IMAGE UPLOADED
$insert->execute();
$insert->close();
$lastImageID = $mysqli->insert_id;
$_SESSION['lastImageID'] = $lastImageID;
$_SESSION['ImageFile'] = $_FILES["fileImage"]["name"];
$sessid = $_SESSION['id'] . ($_SESSION['initial_count'] > 1 ? $_SESSION['sessionCount'] : ''); GET THE NAME OF THE SESSION
$sessionquery = "SELECT SessionId FROM Session WHERE (SessionName = ?)"; //FIND SESSIONID by finding it's SESSIONNAME
// Bind parameter for statement
$sessionstmt->bind_param("s", $sessid);
// Execute the statement
$sessionstmt->execute();
// This is what matters. With MySQLi you have to bind result fields to
// variables before calling fetch()
$sessionstmt->bind_result($sessionid);
// This populates $sessionid
$sessionstmt->fetch();
$sessionstmt->close();
$imagequestionsql = "INSERT INTO Image_Question (ImageId, SessionId, QuestionNo) //INSERT DETAILS INTO CURRENT IMAGE_QUESTION TABLE
VALUES (?, ?, ?)";
if (!$insertimagequestion = $mysqli->prepare($imagequestionsql)) {
// Handle errors with prepare operation here
echo "Prepare statement err imagequestion";
}
$qnum = (int)$_POST['numimage']; //QUESTION NUMBER IMAGE IS UPLOADED IN
$insertimagequestion->bind_param("iii",$lastImageID, $sessionid, $qnum);
$insertimagequestion->execute();
if ($insertimagequestion->errno) {
// Handle query error here
}
$insertimagequestion->close();

Answer 1

Your biggest problem is the fact that your schema isn't normalized. Doing so should help you some.
Here's how I recommend structuring your database:
Session:
SessionId SessionName
3 EROEW
Question:
QuestionId(PK) QuestionContent SessionId (FK)
11 Question1 3
12 Question2 3
13 Question3 3
Image:
ImageId (PK)
1
2
Image_Question:
ImageId (FK) QuestionId (FK) -- (Composite primary key)
1 11
2 12
The insert order for the tables should be:
Session -> Question -
\
-- Image_Question
/
Image -
You'll be dodging potential update issues, and data conflicts otherwise.