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POHow to pass multiple Expressions to OrderBy for EF?
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copied!<p>I am using EF 4.2, but I expect this would apply to EF 4 and 4.1 as well.</p> <p>I would like to pass an <code>IQueryable<T></code> and multiple <code>Expression<Func<TSource, TKey>></code> to a method and have the method apply <code>OrderBy</code> and <code>ThenBy</code> to the <code>IQueryable<T></code> as appropriate.</p> <p>I found <a href="https://stackoverflow.com/questions/5047561/how-to-pass-an-array-of-orderby-expression-to-a-method/5235197#5235197">this answer</a>, and wrote the method below based on that:</p> <pre><code>public IQueryable<User> ApplyOrderBy(IQueryable<User> query, IEnumerable<Expression<Func<User, IComparable>>> orderBy) { if (orderBy == null) { return query; } IOrderedQueryable<User> output = null; foreach(var expression in orderBy) { if (output == null) { output = query.OrderBy(expression); } else { output = output.ThenBy(expression); } } return output ?? query; } </code></pre> <p>This works fine as long as the properties I order by are <code>string</code>s, but when I try to order by an <code>int</code> property, I get an exception:</p> <blockquote> <p>Unable to cast the type 'System.Int32' to type 'System.IComparable'. LINQ to Entities only supports casting Entity Data Model primitive types.</p> </blockquote> <p>Any suggestions to work around this, or for a different approach altogether? I considered passing in an <code>IEnumerable<Expression></code>, but then would need to figure out how to cast back to the specific type (e.g. <code>Expression<Func<User, int></code>) to call <code>OrderBy</code>.</p>

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