Im new to Microsoft entity framework and wonders if it's possible to use this framework with a DB2 iSeries AS/400? Are there any problems at all when working with this kind of "legacy systems"? and the EF framework?
You can use Entity Framework to connect to an ISeries DB2 database one of three ways:
1. If you purchase the license to IBM's DB2 Connect product. The license is around $12,000 which is outrageous. Also, there is not enough good documentation for how the DB2 Connect product actually works, how it installs, or its possible benefits. I've contacted one of their resellers to get a test install and it was not an intuitive process so we never purchased the product. Likewise, there doesn't appear to be any demos. I don't understand how IBM can have one of the best servers available but don't bend over backwards to leverage their product to Microsoft developers.
That said, if you research this topic you will find much information saying that you can use Entity Framework using their ADO.Net data server provider. I went down this path but I will warn you that their data server provider only works when DB2 connect is installed. This is confusing because IBM advertises this ability but doesn't often show the direct correlation between the two products so you're often left thinking that it will work without db2 connect which it will not at this time.
2. Purchase a third party data provider designed for Entity Framework. Progress software's Data Direct is super easy to use. I don't like how their server licensing works though because their server license is per core processor for your app server. This is flawed because this assumes you only have one app server when in reality, people regularly need to have different app servers for load balancing. I would prefer they just license per one ISeries server. However, you can purchase the licenses for each individual user if you decide to do that.
3. Write your own data provider. This is possible but there are obvious drawbacks.
It sort of looks like it is - see here:
but quite honestly, I'm not 100% sure - especially not if it supports EF 4.0 (yet).
Or check out the IBM DB2Connect site and search from there...