I've been playing about with the Entity 4 framework lately and it's pretty nifty. I've setup a class called Customer.cs with some properties like Name, Address etc. I also have a class called StoreEntities.cs which binds these back to the database through DbSet. It works fine and I can pull all my customers from the database.
The problem is every tutorial I come across on the internet generates their classes by hand. What I mean is, they all say something like "Now I'm going to make a new class called Orders with the following properties" and then proceed to write it out. That might be ok if I was starting a new project, but I'm porting over my old website so I have upwards of 20 tables in my database. If I go through and write all these out by hand I'm going to be there all week :D
Plus I'm not sure what would happen if I made some changes to the database (since I would have to go back through and update all my classes by hand).
I was hoping EF4 would have something similar to a Class Diagram, where I can point it at my database and have it generate a bunch of classes for me based on that.
I'm a little lost on this. Am I going about this the right way?
You should take a look at the ADO.NET C# POCO Entity Generator. With that you should be able to generate your model from your existing database and T4 templates will generate your POCO classes based on your databases tables, etc.
Here is a link to MSDN that explains how to Update Model from Database using the Update Model Wizard.
There are two ways to achieve what you want. Both start from adding new item to your project. In the "Add new item" window select "ADO.NET Entity Data Model". There you will have two options. One to generate your model from existing database and second to create model manualy in designer. If you choose first one you can simply drag and drop tables from server explorer to design surface and all your entities and their relations will be generated for you automaticaly. Also you can modify that generated model later.
来源：https://stackoverflow.com/questions/4979361/can-ef4-generate-poco-for-me-or-do-i-have-to-write-them-myself