问题
I'm using Entity Framework 4 and with a Database First binding, and EF is not generating the entities for a few of my tables. I'm not getting any errors, and no matter how many times I select the tables to generate from the "Update Model from Database" popup menu on the design surface, the same tables are still missing from the model.
I get no errors in the wizard. They just don't get generated. Any clues?
回答1:
EF requires a primary key on the table. EF will not map tables for which it can't find or derive a primary key. If all columns are nullable, it can't assume a primary key. If one or more columns are not nullable, EF will evidently derive a primary key for the table.
回答2:
EF will ignore table without primary keys.
回答3:
Options I can think of:
Did you check the box next to those tables?
Did you previously add them, then delete their entities but keep the cache of the tables?
If so you can remove them from entity browser window and re-add them or manually add entities and define the table they map to in mappings window.
Perhaps tables were classified as relations instead of entities?
- You can manually add the entities and choose the table they map to in mappings window.
回答4:
Actually, in my case, it doesn't work because I was using a hierarchyid field as a primary key and EF doesn't work with this field type, so, it didn't import the table, because a valid PK is required.
回答5:
A possibility is when you're using tables with some different field types, as hierarchy in SQL Server.
回答6:
Without Primary Key Tables where Skip Automatically on EF, OtherWise You Fix a Value as Not Null.
来源：https://stackoverflow.com/questions/6127757/why-does-database-first-ef-skip-mapping-some-tables