更新EF6 edmx模型会导致创建新的模型文件

Question

I'm using EF 6.1 with the downloaded T4 template from VS. When I try to update the EF model with new information, or just issue a refresh from my database, the model file duplicates and I get a massive amount of errors.

So, for example, my model file is called Test.edmx, which has subfiles called Test.Designer.vb and TestModel.tt. The TestModel.tt has a subfile called TestModel.vb which appears to contain all my entity framework models.

When I right click on the design surface and select "update model from database", and either add a new entity or refresh an existing one, instead of updating the TestModel.vb file, it creates a whole new file called TestModel1.vb. Once that happens I get thousands of duplicate item exceptions, because now there a doubles.

Why is this happening, and how can I fix it? Is something configured wrong? This model was previously using EF4 and was upgraded straight to 6 using these instructions. https://msdn.microsoft.com/en-us/data/upgradeef6.aspx

Answer 1

It sounds like the linkage between your model/tt file and the output file has been broken. You could open the project (vbproj) file in a text editor and look for test.edmx or testmodel.tt. You should find one or both of them inside nodes somewhere. The file in the enclosing node is the one that depends upon them. At a guess you'll find this is currently TestModel1.vb. You could try editing this and reopening the project, but the simplest thing might be to exclude your existing TestModel.vb and let visual studio have its way. It should be a hidden file after all