I am using VS 2012 and EF 5. I have an existing database that I want to create POCO classes from the existing database. I followed the steps to add an ADO.NET Entity Data
Use EF 5.x DbContext Fluent Generator
You can add it from online templates:
Add New Item
It will add three T4 templates to your project:
BUT you need to setup path to your edmx data model manually. Each of these templates have line string inputFile = @"$edmxInputFile$";
. You need to provide name of your edmx file here:
string inputFile = @"Northwind.edmx";
The process to do this is pretty streamlined now, it seems. The steps from the accepted answer are now easy to do from the EDMX designer itself. Basically,
Open the .edmx file in the Entity Designer.
Right-click an empty area on the Entity Designer surface and point to Add Code Generation Item.
In the Add New Item dialog, select Online Templates and type DBContext in the Search Online Templates text box.
Select the appropriate version for your template (5.0, if you want to target the Entity Framework 5.0).
Click OK.
This will do all the work, apparently. The quoted instructions here refer to Online Templates as installing EF 5.x DbContext Fluent Generator is required. If you have it already installed, there is no need to search for it in the Online Templates but in the Installed Templates.
For more info you can check this page, section "To use the DbContext Generator Template to Generate Object Layer Code".