Check latest id and add 1 [closed] - mysql

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Since I got several "projects" that should contain many questions each, I have a question-page where I fill a videolink, four answers and four drow-down lists where the user is able to set points for every answer.
However, in the database I have two tables.
When I fill and execute my question page I have made so every answer gets an id. In the table "answer_det", Pid, Aid, answer and points is being set. This is how it looks like:
The "question" table when I insert the first question for the first project(Pid=1) :
What I want to do now is to also set the qid(question-id). I'm not sure how to do it, but I think that I should have a code that checks the maximum qid of the pid and add 1 to it so every new question for the same project get a new qid. If the pid isn't in the table, then the qid should get the value "1".
So if you look at the first picture, the qid should be 1 on every showed row since all the four answers belongs to the same question, which is the first one for the project with pid=1. So if I would like to add a question to the same project, it should look the same but with the qid=2 and so on. If I then add a new(first) question for the project 2, the qid should begin on 1 and so on. Then, if i would like to add a new question again for the first project, the code should check that the maximum qid is 2 where pid is 1, and then insert a new question with answers but with qid=3.
It should work the same way on the table "question", which you see on the second picture. When the first question is created, I want the first question for the first project(the one with pid=1) to also have qid=1 and the link that I filled. The second question for the project with pid=1 should then get qid=2. If i add a first question for a new project, it should then be pid=2 and qid=1.
This is the code that I have now, and nothing of it inserts anything in the qid in neither of the two tables.

Answer 1

I suppose you have a predefined set of projects:
Project 1> Science
Project 2> Maths
Project 3> History.....and so on.
I suggest you create a separate table for projects that would have projectID and projectName columns.
Now in your question-page, have these projects in a dropdown(select option) format with projectID as the option value and projectName as the dropdown select name.
Now you have a select option for project name, an input field for question_link and other select options for answers and their weight-age. Now when you insert this form (this question) try coding the following logic (I will just try to write in pseudo-code manner)
//first check if this project already has questions in the question table.
So do something like
SELECT* FROM question WHERE pid = $post['projectID'] ORDER BY qid DESC
// or you could do SELECT TOP 1
// CASE1: if this project never had any questions, the select would return null.
//Hence this is a first question for this project. Then simply write an insert query that
//would insert $post['projectID'] to pid and 1 in qid (since this is the first question).
//Also, insert a series of rows in the answer_det table that will have $post['projectID']
//to pid and 1 for qid and the answer and points as submitted.
// CASE2: if this project already has 1 or more questions, your select query from above
//will return some rows and if you pick $row[0]['qid'], this would be the highest number
//value for question (qid) as we selected using ORDER BY qid DESC. Now, simply do inserts
//in both the tables like you would do as above but this time, in the qid field in both
//the tables, instead of inserting 1, you would insert qid => $row[0]['qid'] + 1.
//You wouldn't need to know what the qid was, all you need is to get the last qid and add
//1 to it.
//Also, you can create a separate page to add the projectName as you feel to add new
//projects and insert this into the project_table and this will begin to show up in the
//select options when you are adding new questions.