Are there any PHP based CMS which could be integrated with an existing database? My client already has a big inventory solution which was written in VBA. Now we need to setup a web based shop for them and we are thinking of setting up a CMS from the shelf.
Is there any way we can integrate the current database scheme with that of CMS ?
That depends entirely on what the big inventory solution does, where it is running, how it is structured, and how the two solutions are supposed to coexist.
Usually though, you will want to make use of existing export/import functions on both sides (e.g. XML) instead of having two applications meddle with the same data base. That often ends in tears.
The issue is that the CMS would have to understand how the database was laid out. Even having a different number of columns would prevent the CMS from understanding the structure of the tables. A CMS isn't a human. It just interacts with data how it's told, it doesn't ever interpret or understand the data.
Your best bet would be to first install a simple CMS with a table prefix (something like installing WordPress with "wp_" as the table prefix) to prevent it from over-writing any existing tables. After this you would need to write a plugin for the CMS which tells it how to read your database. It may be possible to find a plugin which already does what you want and then modify it to use your table design rather than the intended one.
In either case, though, the information in a database is part of the site's content. As such it's the job of the content management system to both create and maintain it. Creating it outside of the CMS will generally confuse it and require some work to integrate it.
first of all, just for curiosity, why cms and not framework? Using framework will ensure you can fully integrate your existing database with less effort (in terms of long-time consistency and reliability).
Still, if you want to stay with CMS, I would recommend Drupal. They have nice feature which allow you to interact with multiple databases without modifying your current data structure. Furthermore, you can build your own customized modules or even installation profile to suits your need.
