Entity Framework 4 not respecting database constraints for numeric fields

问题

Say, I have a table in the DB defined as follows

Table: Foo
PkId - int, primary, autoincrement
Bar - int, allow null=false, no default

Now when generating the EF model from the database the 'Bar' field is correctly defined as Nullable=false, Type=Int32.

Now when I do the following

var foo = new Foo();  
context.AddToFoos(foo);  
context.SaveChanges();

The row is inserted into the database and 'Bar' has a value of 0? I would have expected an exception because Bar hasn't been set. I realise that 0 isn't null but its also not a value that I've set.

Is this by design or have I misunderstood something?

回答1:

It's not nullable and thus an int. The default of int is 0. So the DB is happy and the framework is fine as well.

来源：https://stackoverflow.com/questions/6111251/entity-framework-4-not-respecting-database-constraints-for-numeric-fields