加载嵌入式实体时发生E​​ntityCommandExecutionException

Question

I have a code that gets all products from my DB:

using (var entities = new DataEntities())
        {
            var products = entities.Products.AsQueryable();
            if (!string.IsNullOrEmpty(nameFilter))
            {
                products = products.Where(o => o.Name.Contains(nameFilter));
            }
            var result = products.Select(ProductBuilder.CreateProductDto);
            return result.ToList();
        }

CreateProductDto method:

        public static ProductDto CreateProductDto(this Product product)
    {
        return new ProductDto
        {
            Id = product.Id,
            Name = product.Name,
            IsEnabled = product.IsEnabled,
            KeyPairDto = new KeyPairDto()
            {
                Id = product.KeyPair.Id,
                EncryptedPrivateExponent = product.KeyPair.EncryptedPrivateExponent,
                Modulus = product.KeyPair.Modulus,
                PublicExponent = product.KeyPair.PublicExponent,
            },
        };
    }

It works fine on my colleaugue's machine. But I get EntityCommandExecutionException with the folloing inner exception: There is already an open DataReader associated with this Command which must be closed first. when trying to access product.KeyPair .

Interesting thing is that if I refresh product.KeyPair via Debugger - it loads fine.

Answer 1

Add

MultipleActiveResultSets=true

to the provider part of the connection string within your entity framework connection string (ie the part the defines the data source, initial catalog, etc)