多个数据库的 WCF 配置

Question

I am in the process of converting our win forms application to use a WCF service instead of client calls to a SQL database.

Im not sure whats best practice but we have identical database schemas on about 600 databases.

i was hoping to find a solution here where i in the startup of the winform application declare the WCF service to use this database. as of i'm trying to avoid in every single method to pass a parameter for what connection string to use.

i have some understanding of WCF but i know very little of "public declarations" and the connection context, and have not found any good examples for my scenario.

is this even possible?

if anyone can guide me in the right direction or hand me some sample code it would be very much appreciated! :)

Thanks in advance

Answer 1

WCF does support sessions. So you could pass which database you want to use in the first call, and all other calls would use the value in session.

See: http://msdn.microsoft.com/en-us/library/ms733040.aspx

Answer 2

WCF is a strange API, in that you'll spend the first month not getting it at all and the next several months wondering how you couldn't get it. I can answer some of your questions.

1. The best resource I know of is the Juval Lowry book, although I hear the Bustamante book is also very good.

2. You can spin up the WCF service in Main() before you run the Form

3. For the design you're talking about you will probably need to have a non-default constructor for your service. This is a bit painful and I believe the Lowry book handles it. If not look at IInstanceProvider and IEndPointBehavior

That being said, I don't really see how WCF fits into this design scheme. Its really for communication between a client and server. If you're planning on using it for an SOA type design there are other methods that are a lot cleaner and more light weight. Dependency injection, etc. Can you give a more straightforward example of what you want to do perhaps? I would even suggest a class that simply wraps your database that you pass into all objects that need DB information instead of WCF.