Understanding how to make repository queries asynchronous

Question

I have the following LINQ query in my repository which behaves as expected:

public ICollection<Address> GetManufacterAddressesFromProductId(Guid productId)
{
    return Context.Products
        .First(product => product.Id == productId)
        .Manufacturer
        .Addresses;
}

How do I make this call async? This is my current solution, which seems... overly long?

public async Task<ICollection<Address>> GetManufacterAddressesFromProductIdAsync(Guid productId)
{  
    var product = await Context.Products.FirstAsync(x => x.Id == productId);
    var manufacturerId = product.ManufacturerId;
    return await Context.ManufacturerAddresses.Where(x => x.ManufacturerId == manufacturerId ).ToListAsync();
}

Leaves me feeling like this isn't really doing things properly, as it has to wait for the first call to complete anyway - sort of defeats the point?

Answer 1

In the following way:

public Task<ICollection<Address>> GetManufacterAddressesFromProductId(Guid productId)
{
    return Context.Products
        .Where(product => product.Id == productId)
        .Select(product => product.Manufacturer.Addresses)
        .FirstAsync();
}

Also note that Sync version is not effective. Should be:

public ICollection<Address> GetManufacterAddressesFromProductId(Guid productId)
{
    return Context.Products
        .Where(product => product.Id == productId)
        .Select(product => product.Manufacturer.Addresses)
        .First();
}