concrete5 database workflow - mysql

Question

I'm in the planning stages for a web-based project management/collaboration app similar to Copper Project or PHP Collab, using concrete5 as my framework.
There are a couple of features I want to integrate, but I'm not entirely sure how to accomplish this, looking at how DB tables are generated with blocks.
The functionality I have in mind is as follows:
1) When a new client is created by an account manager or project manager, they have to assign a three-character prefix for the client. Example: if (by some wild stroke of luck) I add Diesel as a client, I would want to assign them the prefix DSL.
2) When an account manager or project manager creates a new project, the project ID should be directly related to the client, and not to the total number of projects for all clients. In other words, the project ID for Diesel's first project with me should be DSL001, and not DSL016, because there were fifteen other projects for other clients before this one (c.f. both Copper and PHP Collab, which follow the global project ID logic, as opposed to the per-client project ID logic). This project ID would be visible on the front-end project page that's been created by the AM/PM, and would also be used as a reference ID for things like cost estimates, invoices and so on.
So this is where I run into a problem from a workflow planning point of view. My understanding of MySQL is such that if I want to follow my own project ID logic, a new table would have to be created for each and every client, to contain all of the data concerning their projects, so that the DB could correctly output the unique ID number.
However, my understanding of C5 is that if, for example, in the course of creating this app, I decide to create the project form as a block to be inserted in a front-end template, the db.xml file would create a generic project data table in the DB for all clients, not one per client.
Any suggestions how I can accomplish what I'm looking to do in the context of C5's framework?
If something's unclear, I can show some mock-ups of how a project page would look.
Thanks!

Answer 1

This is a general database schema issue, and has nothing to do with Concrete5 specifically. Your idea about needing a separate table for each client just so MySQL could generate unique ID numbers is way off.
There is a general principle with database schemas that says the "ID" number of a record should only be used to uniquely identify records internally (within your application and database code) -- you should almost never use the primary id numbers for actual "business logic". In your case, you have a project id that has both letters and numbers in it, so even if you wanted to use the MySQL-generated ID for this, you couldn't (because those id's are integer numbers only, not letters).
Also, creating separate tables for the same kind of data is the exact opposite of how databases work. Instead what you want to do is have one table for clients and another for projects. The client table would have an "id" field (the auto-increment number), and a client prefix field (the "DSL" in your example). Then the projects table has its own "id" field (again, the auto-increment number), and a "client id" which ties that project to a record in the client table. Then you'd have another field in the projects table for "project number". This project number field is what you'd display to users (you'd combine it with the client's 3-letter prefix -- so really you are storing two separate values in the database, but your users would see just one combined value because that is how you would output it to the page).
This "project number" field should not be an auto-increment number, because as you've discovered, MySQL only has one numbering sequence per table. So instead you will have some code in your application somewhere that generates this number for you when you have a new project. That code would be something like this:
function save_new_project($client_id, $project_data) {
$db = Loader::db();
//Determine the highest existing project number for this client
$sql = "SELECT MAX(project_number) FROM projects WHERE client_id = ?";
$vals = array($client_id);
$max_project_number = $db->GetOne($sql, $vals);
if (empty($max_project_number)) {
$max_project_number = 0; //first project for this client
}
//Insert new project with next-highest number
$new_project_number = $max_project_number + 1;
$sql = "INSERT INTO projects (client_id, project_number, some_field, another_field) VALUES (?, ?, ?, ?)";
$vals = array($client_id, $new_project_number, $project_data['some_field'], $project_data['another_field']);
$db->Execute($sql, $vals);
}
By the way, Concrete5 is probably not a good framework to use for this kind of project. You might want to look into a more general framework that is suitable for web applications such as CodeIgniter, Symfony, CakePHP, Kohana, etc.