off-topic [Re: [fpc-pascal] proxy for sql]

Martin Friebe fpc at
Thu Mar 19 15:28:23 CET 2009

Andreas Berger wrote:
> This isn't really a FPC question, but since the application is being 
> written in FPC I thought I would ask here.
> I am developing an application that controls machinery. The 
> application will store everything that happens in a SQL database. Some 
> clients (restricted) should have permission to access the database to 
> generate their own reports via some 3rd party report generation 
> software of their choice. However I want to restrict who has access 
> without placing a user password on the SQL server since some clients 
> purchase multiple instances of the SW but not all options.
> 1) Is it possible to place my app between the 3rd party app and the 
> SQL server? How would I do this.
> 2) Is it possible to configure the SQL server to query my app to see 
> if a user can log on?
> 3) Any other ideas?
> Regards,
> Andreas
Well I imagine that will be hard to do, if you do it in FPC (since you 
may have to start from scratch).
I don't think there is a component emulating the mysql server interface. 
Rewriting the server (just the protocol part) is a lot of work.

You may want to look at the mysql site, they have a mysql-proxy, which 
can be controlled by LUA script. So that my do the trick for you. You 
could probably replace the client credentials inside the proxy. Make 
sure you forward using a restricted account. Otherwise you must ensure 
that nothing in the sql could ever violate the permissions.

Best Regards

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