Question

I’ve got a scenario where I will need to order by on a column which is a navigation property for the Users entity inside my EF model.

The entities:
Users –> Countries 1:n relationship

A simple SQL query would be as follows:

SELECT UserId, u.Name, c.Name
FROM users u join countries c on u.CountryId = c.CountryId
ORDER BY c.Name asc;

So then I tried to replicate the above SQL query using Linq to Entities as follows – (Lazy Loading is enabled)

entities.users.OrderBy(field => field.country.Name).ToList();

But this query does not return my countries sorted by their name as the native SQL query above does.

However I continued a bit more and did the following:

var enumeratedUsers = entities.users.AsEnumerable();
users = enumeratedUsers.OrderBy(fields => fields.country.Name).ToList();

But ordering on the enumeratedUser object for about 50 records took approx. 7seconds

Is there a better way how to omit the Enumerable and without returning an anonymous type?

Thanks

EDIT

I just forgot to say that the EF provider is a MySQL one not a MS SQL. In fact I just tried the same query on a replicated database in MS SQL and the query works fine i.e. the country name is ordered correctly, so it looks like I have no other option apart from getting the result set from MySQL and execute the order by from the memory on the enumerable object

Answer 1

SOLUTION

Since I had both columns named Name in both Countries and Users table MySQL Connector was generating this output when order by country.Name was executed:

SELECT `Extent1`.`Username`,  `Extent1`.`Name`,  `Extent1`.`Surname`, `Extent1`.`CountryId`
FROM `users` AS `Extent1` INNER JOIN `countries` AS `Extent2` ON `Extent1`.`CountryId` = `Extent2`.`CountryId`
ORDER BY `Name` ASC

therefore this will result in ordering on the users.Name rather countries.Name

However MySQL have release version 6.4.3 .NET connector which has resolved a bunch of issues one of them being:

We are also including some SQL generation improvements related to our entity framework provider. Source: http://forums.mysql.com/read.php?3,425992

Thank you for all your input. I tried to be clear as much as possible to help others which might encounter my same issue.