.net – LINQ to Entities does not recognize the method Int32 get_Item(Int32)

entity-frameworklinqnet

I am a newbie about entity framework and linq. My query is like that

var query = (from d in db.MYTABLE
             where d.RELID.Equals(myInts[0])
             select d.ID).Distinct();

List<int?> urunidleri = query.ToList();

When i execute this code, i got the error message "LINQ to Entities does not recognize the method Int32 get_Item(Int32)". How can i solve my problem ?

Thanks…

Best Answer

You need to store your int in a variable, so that EntityFramework isn't trying to pull the whole array into its scope.

var myInt = myInts[0];

var query = (from d in db.MYTABLE
             where d.RELID.Equals(myInt)
             select d.ID).Distinct();

List<int?> urunidleri = query.ToList();

Related Solutions

C# – The entity cannot be constructed in a LINQ to Entities query

You cannot (and should not be able to) project onto a mapped entity. You can, however, project onto an anonymous type or onto a DTO:

public class ProductDTO
{
    public string Name { get; set; }
    // Other field you may need from the Product entity
}

And your method will return a List of DTO's.

public List<ProductDTO> GetProducts(int categoryID)
{
    return (from p in db.Products
            where p.CategoryID == categoryID
            select new ProductDTO { Name = p.Name }).ToList();
}

.net – LINQ to Entities does not recognize the method

As you've figured out, Entity Framework can't actually run your C# code as part of its query. It has to be able to convert the query to an actual SQL statement. In order for that to work, you will have to restructure your query expression into an expression that Entity Framework can handle.

public System.Linq.Expressions.Expression<Func<Charity, bool>> IsSatisfied()
{
    string name = this.charityName;
    string referenceNumber = this.referenceNumber;
    return p => 
        (string.IsNullOrEmpty(name) || 
            p.registeredName.ToLower().Contains(name.ToLower()) ||
            p.alias.ToLower().Contains(name.ToLower()) ||
            p.charityId.ToLower().Contains(name.ToLower())) &&
        (string.IsNullOrEmpty(referenceNumber) ||
            p.charityReference.ToLower().Contains(referenceNumber.ToLower()));
}

Best Answer

Related Solutions

C# – The entity cannot be constructed in a LINQ to Entities query

.net – LINQ to Entities does not recognize the method

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