Question

I want to use SqlFunctions.StringConvert() in many places in different projects in my solution.

I dont want each project to hold reference to system.data.entity so I decided to put a wrapper in my Common project (all other projects has reference to Common).

How can I write such wrapper? If I am doing:

public static class SqlUtils
{
    public static Func<decimal?, string> StringConvert()
    {
        return x => SqlFunctions.StringConvert(x);
    }

    public static Func<double?, string> StringConvert()
    {
        return x => SqlFunctions.StringConvert(x);
    }        
}

Then I cannot use it like:

query.Where(x => SqlUtils.StringConvert((decimal)x.SerialNumber).Contains(serialNumber));

because entity framework don’t know the method SqlUtils.StringConvert.

Any ideas how to do it?

Answer 1

If you want EF to be able to translate it all down to SQL, you have to more work, see: http://blogs.microsoft.co.il/blogs/gilf/archive/2010/01/01/defining-custom-functions-in-entity-framework.aspx