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POCreate new Linq SelectMany extension method
 

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    <p>I am using Linq.Dynamic. I have already added another SelectMany extension to all for creating a new anonymous object with the data. But, I have ran into another issue that I can not seem to solve. </p> <p>I want to have extension method chaining as follows, but using the dynamic methods:</p> <pre><code>var customerandorderflat = db.Customers .SelectMany(c =&gt; c.Orders.SelectMany(o =&gt; o.Order_Details, (ord, orddetail) =&gt; new { OrderID = ord.OrderID, UnitPrice = orddetail.UnitPrice }).DefaultIfEmpty(), (cus, ord) =&gt; new { CustomerId = cus.CustomerID, CompanyName = cus.CompanyName, OrderId = ord.OrderID == null ? -1 : ord.OrderID, UnitPrice = ord.UnitPrice }); </code></pre> <p>Ideally I would like to chain the dynamic SelectMany as follows:</p> <pre><code>db.Customers.SelectMany(c =&gt; c.Orders.SelectMany("Order_Details", "new(outer.OrderID, inner.UnitPrice)"), "new(outer.CustomerID, inner.OrderID)"); </code></pre> <p>Or something to that affect. The problem is that I can not get a signature to match.</p> <p>I have tried many different options to get it to allow chaining. But it just doesn't work. I am thinking ideally it would look like this:</p> <pre><code>public static IQueryable SelectMany(this IQueryable source, IQueryable innerExpression, string resultsSelector, params object[] values) </code></pre> <p>But, it doesn't recognize c => c.Orders as IQueriable. I also need to figure out how to do DefaultIfEmpty on the results to allow for LEFT JOINs.</p> <p>Please help.</p>
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