问题
Unfortunately this question may be a little broad, because I can't work out the proper terms to help me bring all this together. I'm very new to php/SQL, and I'm attempting to set up a minimal site with very simple login/register functionality.
- Should I be creating a new database user whenever I register a new web user?
- Are CRUD privileges safe to give to all users of the website?
Should I actually make a DB user for registering, one which can only insert into the user table and nothing else until they login (requiring no password for mysqli_connect())?
Once logged in, they would make a connection to a different type of DB user, one with more privileges to use the website.
- How many different types of DB users should there be?
I assume a small group of users for the DB workers (including one for root access), another group for each type of web user (ie. employers have more privileges than employees), and another restricted user just for registering.
- All in all, would >10 DB users in a small website be unusual?
- Is there a performance/space cost associated with having many types of users?
I appreciate any responses and links, and apologize if these are very basic questions.
回答1:
I struggled with this all those years ago, so here is the answer I wish I had:
Generally, this is overcomplicating things, and the headline answer for a basic application is: the permissions of users will be managed by the PHP code in the API calls you make, and one DB user is fine. All users should avoid interacting directly with the DB for app dev generally, to prevent violating the sanctity of the data.
It's good to think about security and restrictions, but simplicity is king - the more complex you make it, the harder it is to maintain, and therefore the easier it is to miss corner cases.
Should I be creating a new database user whenever I register a new web user?
No, database users are distinguished by their privileges. As a result, all users conform to a set of groups with varying privilege levels. The database accounts are separate from the web accounts - connecting to the database is done behind the scenes and has no link to the web account being used.
A good approach would be to create a DB account for each service connecting directly to the DB. For the vast majority, this will be one service, your web server. If the application grows and isolated services such as audits, microservices, security, IOT spring up, they should probably have their own accounts.
Are CRUD privileges safe to give to all users of the website?
The question is misguided - you give the CRUD to the DB account, which will need it. For the CRUD permissions managed inside the PHP, it really depends on your app and specific endpoints. For example, you probably don't want all your users to be able to delete User records, so your PHP code should prevent that from happening.
How many different types of DB users should there be?
The number depends on your database. Generally, there are 4 groups
- Database Administrators
- Database Designers
- Casual End Users
- Native End Users
However, if you want to grant table level privileges then you might need to branch out a little more. This would suggest 10 DB accounts is quite a small amount, several hundred is more likely.
The more privileges, the more space is required, but it's a fairly minute consideration, and shouldn't play a big role in performance. Complexity is the next issue - think carefully how many groups and permutations you actually want to test. In the case of the question above, I was a single hobbyist developer - one account as a DBA is probably fine. If there were multiple users directly accessing the DB (already probably a bad idea for app dev), then maybe split out them with varying permissions.
Talking about table level permissions for a simple app is just way overkill!
来源：https://stackoverflow.com/questions/24397002/mysql-application-users-vs-database-users