All Questions
21 questions
2
votes
1
answer
91
views
How add MemberInitExpression into Bindings other Lambda MemberInitExpression
I have the following classes:
class Source {
public int Id { get; set; }
public string Name { get; set; }
public SourceItem Item { get; set; }
}
class SourceItem {
public Guid Id { ...
1
vote
2
answers
479
views
Proper way to query DataContext using Group by that has fields with Nulls
I'm using Entity Framework, And I'm querying the Data using a Group By clause. In the Group by there are multiple columns that have to be used. Some of the columns can have nulls. The issue is that ...
- 660
1
vote
2
answers
407
views
Create a Linq to entities IQueryable extension for date grouping (GroupBy)
I am trying to build an expression tree for a custom grouping by date, transform this:
groupedData = entity.GroupBy(e => new DateTime(e.created_date.Year, 1, 1));
Into an extension that does not ...
- 255
0
votes
0
answers
264
views
Using a function defined as a Linq.Expression in VB.NET
I found this question's accepted answer very informative to use Expressions with Linq to Entities. I can't figure out the VB.NET syntax, however.
Given something like (this part being in C# is fine)
...
- 16.7k
1
vote
1
answer
80
views
Is there a way to more easily combine Expressions and lambdas?
Let's say I have an Expression<Func<Foo, Bar>> calculateBar which 'reduces' a Bar into a Foo, which I can use like so:
IQueryable foo = getFoos();
bars = foo.Select(calculateBar);
However,...
- 1,199
-1
votes
2
answers
282
views
Is it possible to simplify this LINQ expression for Entity Framework?
I'm implementing a basic search service, and several different repositories are injected into it. The repositories have a method that allows for an expression to be used like so:
public ...
- 6,198
1
vote
1
answer
872
views
LINQ Expression for CROSS APPLY two levels deep
Fairly new to LINQ and am trying to figure out how to write a particular query. I have a database where each CHAIN consists of one or more ORDERS and each ORDER consists of one or more PARTIALS. The ...
- 23
0
votes
1
answer
1k
views
"LINQ to Entities does not recognize the method 'Boolean ***, and this method cannot be translated into a store expression."
I am coding a MVC 5 internet application, and am getting the following error:
base = {"LINQ to Entities does not recognize the method 'Boolean ...
- 8,351
0
votes
2
answers
1k
views
Entity Navigation Property IQueryable cannot be translated into a store expression
im using Entity Framework designer first and I need to create custom Model Objects starting from the db objects.
I don't want to use IEnumerable cause it will query too many fields.
The goal is to ...
- 342
12
votes
4
answers
25k
views
Dynamically add new lambda expressions to create a filter
I need to do some filtering on an ObjectSet to obtain the entities I need by doing this :
query = this.ObjectSet.Where(x => x.TypeId == 3); // this is just an example;
Later in the code (and ...
user2324540
2
votes
1
answer
5k
views
Cross-Join Syntax in Entity Framework / IQueryable
I'm trying to deepen my education about IQueryable custom providers and expression trees. I'm interested in custom parsing a cross-join (viz. SelectMany), and I'm trying to understand if that is ...
- 30.2k
0
votes
1
answer
118
views
In join how to segregate the select statement
In my project one table is connected with two or more tables ,To require wanted out put need to join them,Join is not my problem ,after join want to select desired column but from a segregate ...
- 6,778
-1
votes
1
answer
160
views
Linq Expression on sub child entities for n levels
Need Generic expression for the below Query.
I don't want to use the Dynamic library and Predicate builder.
I am generating expressions dynamically.
var test = entity.User.Where(PUser => PUser....
- 39
1
vote
2
answers
1k
views
linq to entities and store expression
I work on project that use some dynamic linq query to an entities.
i have huge amount of case and to avoid code duplication i refactoring to a method.
But using method which isn't in store expression ...
- 39
5
votes
2
answers
2k
views
EF orderby / thenby combo extension method
I want to be able to apply combo firstby / thenby sorting as follows:
allOrders().sort(s => s.ProductName, s => s.OrderDate)
So using this post as inspiration, I wrote this extension method, ...
- 2,325