使用EF6异步查询结果

Question

I have a query that results in a 300 - 500 result set. I know it's not many items but it does take a long time to compute, something like 60 to 90 sec...
When I run the query generated by EF6 on Management studio I get 2-3 new rows each second.
I would like to replicate this behavior in my grid, eg: feed the grid new rows as they become available.

Is there a way to do this using EF6?

Using the "async" keyword/method forces the whole operation to hang... I used to do this using BeginExecuteReader + callback and some settings on SqlConnection...

Answer 1

There doesn't seem to be a lot of documentation about it but it appears that Entity Framework 6 added the ForEachAsync extensions method:

http://msdn.microsoft.com/en-us/library/system.data.entity.queryableextensions.foreachasync(v=vs.113).aspx

Code example found on this blog

using (var context = new DataContext()) {
    await context.Manufacturers.ForEachAsync(m => Console.WriteLine("{0} : {1}", m.Name, m.Country));
}

In your item callback you could just send the results back to the UI as they become available.