Database Driven Logins

jesuslover037

Hey guys, I'm starting a PHP, web-based program that allows schools to store specific information in a database. So far I've had alot of success, only there's one problem--I'm the only user. I want to make each school have its own database, but I'm unsure how to do this. Should I somehow make a login page and store the values into a table on the database? But then how would I select databases based off those values? Really, I just need some ideas and input. I'm not asking to give me 5 pages of code--just some pointers or suggestions. Thanks alot!

wilku

jesuslover037 wrote:
I want to make each school have its own database, but I'm unsure how to do this.

Does every school store huge ammounts of information that you want to create a separate database for each? You can store it all in one database. An example: let's say you want to store staff information for each school. First you create a table with schools, storing information about each school in rows. Then you create a table for staff members. The third table can cross reference between those tables (in one row there would be and id of a school with an id of a staff member). And so on (all the information can be cross referenced with school table). And so you'll have the information about different schools in one database.

jesuslover037 wrote:
Should I somehow make a login page and store the values into a table on the database?

Yes. There are many examples on the net of how to build account management systems with permissions system - search in Google

jesuslover037 wrote:
But then how would I select databases based off those values?

If you really want to, there is [man]mysql_select_db[/man] to do this - but then you'd have to store account - database relations somewher (in a separate database?). No, really - it would be too complicated... I'd stick to one database, if I were you.

PS. I love Jesus too 😉

jesuslover037

Thanks, wilku, that was a very informative response. It would be nice to have them in one database, unfortunately(or fortunately depending on how you look at it) I am hoping this program to spread fairly large, so I don't want to have to go back later when a lot of users are registered and have to rush to write code that could end up buggy--I want to go ahead and make it expandable and flexible right now.

I've managed to do a login system right now that I'm still working the kinks out of that logs the user into his database based off the login name he supplies and the password. This information is stored in a users database. It seems to be working fairly well. Thanks for the reply though. It was very helpful.

Piranha

Unfortunatley most pages never spread as large as anticipated. I don't mean to scare you, I'm just saying that the time to use several databases is when you know for a fact it is going to be big. Or never, I would recommend using one database no matter how big it gets. More about this further down.

The pros of using one database:
- It is easy to upgrade the software, you only need to change in one database.
- You don't have to invent ways to use different databases.
- It most defenetely is expandable.
- You only have to administer one database

The pros of using several databases:
- It is easier to customize for different schools.

The only pro of using several databases that I can come up with is to make it easier to customize for different schools. But if you do that you should use code and a database that is specific for that school anyway, breaking that school out of the big database and give it a whole application for itself.

Letäs say that it gets fairly big, you have 1000 schools. Then you expand the application with another database table and a few references to that table in the current tables. With one database you would just have to update that one database, and it is easy to test it afterwards. Total time for update and test: about one hour. If you have 1000 databases you first have to update all the databases, then test them all. Or just update and hope that you didn't miss any database. Total time with update and test: at least 200 hours. Total time with only update: at least 40 hours.

So if you don't have any reason that you can say "this is exactly why I need several databases" use one database. Vague reasons like "expandable and flexible" is no reason since it doesn't say anything clearly.