LINQ to SQL cross apply

Question

I would like to create a query with a cross apply into a user defined table value function in LINQ. The SQL would be really rather simple as below:

SELECT *
FROM MyTable mt
CROSS APPLY MyTVF(mt.id)

This post gives an example of a LINQ query that results in generated sql that contains both a cross apply and an outer apply but only for a sub query not for a tvf. This article confirms that LINQ to SQL will generate cross apply and outer apply operators for "relationship navigations" but I am not sure what that means in this context. This post describes pretty much what I want to do and the answer says the only way to do this is to wrap the SQL query in a stored procedure and then call the sp via LINQ. I hope that this is not true because I actually need a tvf that can be used in this way throughout an application in multiple LINQ queries so "wrap it in an sp" would not work for me. Does anyone know of a way to get something like the simple SQL statement above via LINQ?

Answer 1

How about this:

from mt in db.MyTable
from mf in db.MyTVF (mt.id)
select new { mt.Blah, mf.Blah }

Answer 2

    var query = ActivityRepository.Where(p => p.iAction > -1 && userIds.Contains(p.iSellerId)).GroupBy(c => c.iSellerId).Select(c => c.OrderByDescending(cc => cc.dBeginTime).First()).Select(a => new ActivityInfo
        {
            ActivityId = a.iActivityId,
            StartTime = a.dBeginTime,
            SellerId = a.iSellerId,
            EndTime = a.dEndTime,
            ActivityName = a.sName,
        });

the keypoint is :.Select(c => c.OrderByDescending(cc => cc.dBeginTime).First())