entity-framework Archives

C#, Programming

IT Nursery

Setting unique Constraint with fluent API?

I’m trying to build an EF Entity with Code First, and an EntityTypeConfiguration using fluent API. creating primary keys is easy but not ...

June 3, 2022
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C#, Programming

IT Nursery

How to add/update child entities when updating a parent entity in EF

The two entities are one-to-many relationship (built by code first fluent api). public class Parent { public Parent() { this.Children = new List<Child>(); ...

June 3, 2022
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.net, Programming

IT Nursery

Getting exact error type in from DbValidationException

I have the situation where I’m initializing my model in DatabaseInitializer() for EF 4.1 and get this annoying error "Validation failed for one ...

June 2, 2022
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C#, Programming

IT Nursery

Update Row if it Exists Else Insert Logic with Entity Framework [closed]

Closed. This question is opinion-based. It is not currently accepting answers. Want to improve this question? Update the question so it can be ...

June 2, 2022
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linq, Programming

IT Nursery

Entity framework linq query Include() multiple children entities

This may be a really elementry question but whats a nice way to include multiple children entities when writing a query that spans ...

June 1, 2022
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C#, Programming

IT Nursery

The cast to value type ‘Int32’ failed because the materialized value is null

I have the following code. I’m getting error: “The cast to value type ‘Int32’ failed because the materialized value is null. Either the ...

May 31, 2022
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ASP.NET, Programming

IT Nursery

ASP.NET Identity DbContext confusion

A default MVC 5 App comes with this piece of code in IdentityModels.cs – this piece of code is for all the ASP.NET ...

May 30, 2022
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Programming, sql

IT Nursery

The object ‘DF__’ is dependent on column ‘’ – Changing int to double

Basically I got a table in my EF database with the following properties: public int Id { get; set; } public string Title ...

May 30, 2022
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entity-framework, Programming

IT Nursery

What’s the difference(s) between .ToList(), .AsEnumerable(), AsQueryable()?

I know some differences of LINQ to Entities and LINQ to Objects which the first implements IQueryable and the second implements IEnumerable and ...

May 29, 2022
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C#, Programming

IT Nursery

How to force LINQ Sum() to return 0 while source collection is empty

Basically when I do the following query, if no leads were matched the following query throws an exception. In that case I’d prefer ...

May 29, 2022
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