tagged [linq-to-entities]

How do I get the max ID with Linq to Entity?

How do I get the max ID with Linq to Entity? I have a table User which has an identity column `UserID`, now what is the correct Linq to Entity line of code that would return me the max `UserID`? I've ...

Select most recent records using LINQ to Entities

Select most recent records using LINQ to Entities I have a simple Linq to Enities table to query and get the most recent records using Date field So I tried this code: > Error: NotSupportedException:...

3 May at 20:49

New transaction is not allowed because there are other threads running in the session LINQ To Entity

New transaction is not allowed because there are other threads running in the session LINQ To Entity Any ideas on why this could be breaking? I read that the workaround the issue, is

10 Apr at 21:52

Updating Entity Framework Model

Updating Entity Framework Model I have just started using EF and found it cool, but I ran into a problem, I changed my DB schema of a column inside the table User, It was Varbinary(50) previously I th...

Entity Framework 4.1 Linq Contains and StartsWith

Entity Framework 4.1 Linq Contains and StartsWith I am using Entity Framework Code First. I want to query entites from database against List objects. This works fine with contains, but how can I combi...

"A lambda expression with a statement body cannot be converted to an expression tree"

"A lambda expression with a statement body cannot be converted to an expression tree" In using the , I get the error "`A lambda expression with a statement body cannot be converted to an expression tr...

Get distinct records using linq to entity

Get distinct records using linq to entity Hi I'm using linq to entity in my application. I need to get distinct records based on one column value "Name" So I have a table similar like you can see belo...

22 Aug at 16:19

String.IsNullOrWhiteSpace in LINQ Expression

String.IsNullOrWhiteSpace in LINQ Expression I have the following code: And I get this error when I try to run the code: > LINQ to Entities d

18 Jul at 17:54

How to create LINQ Expression Tree to select an anonymous type

How to create LINQ Expression Tree to select an anonymous type I would like to generate the following select statement dynamically using expression trees: I have worked out how to generate ``` var v =...

EF Distinct (IEqualityComparer) Error

EF Distinct (IEqualityComparer) Error Good Morning! Given: ``` public class FooClass { public void FooMethod() { using (var myEntity = new MyEntity) { var result = myEntity.MyDomainE...

How to get a byte array length using LINQ to Entities?

How to get a byte array length using LINQ to Entities? I have a Document class that stores the data of that document as a byte array. I need to check the size of the array, using LINQ to Entities. I h...

21 Oct at 13:51

Error: The object cannot be deleted because it was not found in the ObjectStateManager

Error: The object cannot be deleted because it was not found in the ObjectStateManager Trying to get a handle on Entity Framework here and I am hitting some speed bumps... I have a Get() method that w...

25 Jun at 04:22

two conditions checking in where clause using linq 2 entites

two conditions checking in where clause using linq 2 entites hi i have table called products with columns anorther table categories with columns ``` category_id(1,2,3.......) category_name(a,b,...

How to initialize IEnumerable<Object> that be empty and allow to Concat to it?

How to initialize IEnumerable that be empty and allow to Concat to it? I tried this code for adding `b` to `books`: but gives me this error on last line of code: > System.ArgumentNullException: Value ...

LINQ to Entities Group By expression gives 'Anonymous type projection initializer should be simple name or member access expression'

LINQ to Entities Group By expression gives 'Anonymous type projection initializer should be simple name or member access expression' I am getting the above mentioned error with this expression: ``` va...

22 Jun at 21:44

How to use DateTime.AddDays(x) in Entity Framework

How to use DateTime.AddDays(x) in Entity Framework I have this code: It does not work, because AddDays() is not possible to use for generating sql. So is there some another way? Now i sele

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

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 nu...

The LINQ expression node type 'ArrayIndex' is not supported in LINQ to Entities

The LINQ expression node type 'ArrayIndex' is not supported in LINQ to Entities ``` public List GetpathsById(List id) { long[] aa = id.ToArray(); long x; List paths = new List(); for (int i ...

How to get first record in each group using Linq

How to get first record in each group using Linq Considering the following records: ``` Id F1 F2 F3 ------------------------------------------------- 1 Nima 1990 10 2 ...

10 Dec at 12:24

What to return from my linq to entities query

What to return from my linq to entities query So I have a data access class library I make a linq to entities call I end up with a single row that has my TableData object. What should I return back fr...

10 Sep at 15:26

How to do SQL Like % in Linq?

How to do SQL Like % in Linq? I have a procedure in SQL that I am trying to turn into Linq: The line I am most concerned with is: I have a column that stores the hierarchy like /1/3/12/ for examp

Problem with converting int to string in Linq to entities

Problem with converting int to string in Linq to entities ``` var items = from c in contacts select new ListItem { Value = c.ContactId, //Cannot implicitly convert type 'int' (Cont...

1 Jul at 00:20

Error: An expression tree may not contain a dynamic operation

Error: An expression tree may not contain a dynamic operation I use Asp.Net 4 and C#, I use EF 4. I have this query, I receive an error: --- It seems is imposible to Cast a Dynamic Type usi

19 Aug at 07:56

LINQ To Entities Contains Case In-Sensitive Searching

LINQ To Entities Contains Case In-Sensitive Searching i am trying to query my resultset like this in linq to entities; However, i don't get any result becuase the `CategoryName` is `For(Upper Case)` i...

12 Mar at 13:50

Cannot assign void to an implicitly-typed local variable

Cannot assign void to an implicitly-typed local variable ``` var query = rep.GetIp() // in this line i have the error .Where(x => x.CITY == CITY) .GroupBy(y => o.Fam) .Select(z => new I...