Expression Tree Tutorial - Knowledge Base (KB)

Intercept all EF6 Linq queries

I have a function which I want to run on every executed Linq query on a DbContext to modify the expression tree before execution. I've been having a look at the IDbCommandTreeInterceptor interface but that doesn't seem to provide an expression tree (whic...

LINQ to Entities OrderBy Expression Tree

I am trying to write a LINQ query to orderBy a dynamic property given by a string value....Here is what my original code was:... Expression<Func<T, dynamic>> orderBy = i => i.GetType().GetProperty("PropertyName").GetValue(null); ...When I tried to run thi...

LINQ to Entities only supports casting EDM primitive or enumeration types (unique new post)

Preface...I counted probably 20 questions pertaining to this particular error, but I did not find that any of them apply. I am doing something different in that I am creating my expressions programatically rather than by literal lambda syntax. I suspect...

Entity Framework + DayOfWeek

Using the ...System.Linq.Dynamic... (managed here ...https://github.com/kahanu/System.Linq.Dynamic... ), I am trying to capture the ...DayOfWeek... field found on the ...DateTime... for aggregation purposes using Entity Framework 6 (or greater)....Previou...

Linq: let statement as a constant?

I am working on a Linq query expression statement, and want to use a ...let... statement to set a constant value as part of the query to reduce potential errors. ...In my example... (this is total mock up). the let statement "validateCount" is the questio...

Modify the expression tree of IQueryable.Include() to add condition to the join

Basically, I would like to implement a repository that filters all the soft deleted records even through navigation properties. So I have a base entity, something like that:...public abstract class Entity { public int Id { get; set; } public bool...

How to extract a where clause expression tree from IQueryable

I need to add an "Or" clause in a where clause dynamically, depending on some conditions to an existing IQueryable object. ...Using ExpressionBuilder, I can compose a left and right Expression> but for that to wrok, I need to extract the Expression> from ...

Accessing expression bodied members to build expression trees

Trying to build an order by expression using expression trees. But I am unable to access an expression bodied property of the query result's class. This is the class structure:...public class AssetFileRecord : IAuditable, IEntity, INavigateToCustomValues ...