Question

How do I get the trace string for a query like this:

var product = _context.Products.Where( p => p.Category == "Windows" )
                               .SingleOrDefault();

// I can't do this since product is not an ObjectQuery instance
// product.ToTraceString();

Answer 1

Different answer for different problem.

You can’t call ToTraceString() on this:

var product = _context.Products.Where( p => p.Category == "Windows" )
                               .SingleOrDefault();

You can do this:

var q = _context.Products.Where( p => p.Category == "Windows" )
var ts = ((ObjectQuery)q).ToTraceString();
var product = q.SingleOrDefault();

… but it’s not 100% accurate. The MSSQL EF provider will use a TOP 2 for Single which this will miss.

You can come close with this:

var q = _context.Products.Where( p => p.Category == "Windows" )
var ts = ((ObjectQuery)q.Take(2)).ToTraceString();
var product = q.SingleOrDefault();

…which should get you the right SQL but requires knowledge of the implementation.

Original question misrepresented the problem. My original answer was:

var ts = (product as ObjectQuery).ToTraceString();