尝试向 edmx 文件添加新视图不会创建

Question

I created an ADO.NET Entity Data Model and now I want to add a new view to it. I found this source and went through the steps but the new view is not adding to the Model. Here is the steps I followed:

1) Right Clicked on my .edmx file and chose Open With
2) Chose ADO.NET Entity Data Model Designer
3) Right Clicked in the Data Model Designer (in the Add tab) and chose Update Model From Database
4) Checked off my new view and hit finish
5) Saved the Model Designed and said okay to the scripts running

After Which my new view is not in the Model Designer or is there a new class in my solution explorer. What am I missing? What else would someone need to see to help me diagnose this?

Answer 1

Entity Framework DB first will often ignore your view if you don't have a primary key defined.

If you wish to make it work, in DATABASE, use the ISNULL() function and/or unique constraint on one of your field. Make sure this field is unique.

Refer to this question if needed :

Views,Entity,Cannot deduce a primary key

For a combination of 2 fields being unique, one simple but not very clean way is to add another column in your view, containing a concatenation of the two fields and put them in isnull(). Suppose it's two nvarchar(5) :

select isnull(columnA + columnB, '1234567890'), columnA, columnB, ...