Entity framework DbContext update value without query and by foreign key

c#, dbcontext, entity-framework-5, updates

Solution

TestProcess pr = new TestProcess()
{
    MyID == id,
};

context.Set<TestProcess>().Attach(pr);

pr.UpdateID = updateID;

context.SaveChanges();

If you are setting the value to the default value of that type (for example, setting an `int` to `0`) it won't be picked up as a change, and you need to manually set the state.

pr.UpdateID = updateID;
context.Entry(pr).Property(p => p.UpdateID).IsModified = true;

You can put such code away in extension methods, so you can do things like this (I'll leave the implementation as an exercise):

Foo entity = this.DbContext.GetEntityForUpdate<Foo>(
    item => item.ID, model.ID
    );

this.DbContext.UpdateProperty(entity, item => item.Name, model.Name);

Problem

I have a method for updating some tables. For update I need get first of `TestProcess`, but I don't like that. How can I update `TestProcess` without `select(firstOrDefault)` operation, used only for the update operation? Example of method: ``` public void UpdateTestProcess(int id, string updateID) { using (TestEntities context = new TestEntities()) { TestProcess pr = context.TestProcess.FirstOrDefault(x => x.MyID == id); pr.UpdateID = updateID; context.TestProcess.Attach(pr); context.ObjectStateManager.ChangeObjectState(pr, EntityState.Modified); context.SaveChanges(); } } ```

Original source

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