Overriding default value in Entity Framework when StoreGeneratedPattern = Computed

Question

Using SQL and EF 6 (C#), I have read multiple posts on this but with no clear solution.

The problem is simple, I want to have a 'default unless otherwise provided' value in the database.

So, I set the default in the database like so:

[notification_sent] BIT NULL DEFAULT ((0)),

Then turn the StoreGeneratedPattern to 'Computed' in the EDMX (using database first).

Is there not a way to now set this field to true?

Below is what the Properties looks like from in VS. If I put this property back to 'none' then it overwrites the value with NULL if I do not provide a value in my code vs using the Default value of 0 as set in the database.
It seems to me that it should be filling in the 'Default Value' field here when it (Visual Studio) generates the .edmx from the database.

I have tried setting 'Nullable' in the above properties to 'true' and it still shows the exact same as before:

public Nullable<bool> notification_sent { get; set; }

In the generated .cs

If I manually insert a value of 'false' in the 'Default Value' field it add the below:

this.notification_sent = false;

But will this not be overwritten when ever I do a refresh from the database?

thanks for the edit Marc_s -- I should not have rushed writing it so much. — Joe Ruder
– Joe Ruder, Commented Feb 12, 2020 at 17:07
The question is quite old, but ever got a satisfying solution to this? — Kai Hartmann
– Kai Hartmann, Commented Nov 18, 2020 at 12:47

Ricardo Peres · Accepted Answer · 2020-02-13 10:01:42Z

0

You don't want to set the StoreGeneratedPattern to Computed, because this means that it's the database's responsibility to create the value for you. You are right in creating a value that is nullable with a default value, but in that case you should map it to a nullable boolean, e.g., your property should look something like this:

bool? NotificationSent { get; set; }

Or some other name. You can either set a value or not, if you don't, the database will set it for you, as 0 (false). This has nothing to do with being computed or not, it's just the default value.

edited Feb 13, 2020 at 10:01

answered Feb 12, 2020 at 16:38

Ricardo Peres

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14 Comments

Joe Ruder Over a year ago

This however is Database first, not code first so I should not change that from what I understand.

Ricardo Peres Over a year ago

You can change the properties on the generated model, right?

Joe Ruder Over a year ago

Yes, I can change them. Are you referring to the 'properties' tab from the model.edmx screen? Or are you talking about the actual model itself (table_name.co) which has: // <auto-generated> // This code was generated from a template. // Manual changes to this file may cause unexpected behavior in your application. // Manual changes to this file will be overwritten if the code is regenerated.

Joe Ruder Over a year ago

So, yes...that is how I set the property referred to in the question: "Then turn the StoreGeneratedPattern to 'Computed' in the EDMX (using database first)."

Joe Ruder Over a year ago

thank you....I am using Core in all new development and you are correct, it is much better. This is a legacy app and would prefer to not have to switch right now. I think you have pointed me the right direction enough on this, I just need to test tomorrow and should be able to close this out.

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