The string concatenation behaviour in SQL server is different from the string concatenation behaviour in C# and causes confusion.
the default in SQL server (and apparently this will not be changeable in the future
) is that concatenating a value with null results in null. In C#, the same concatenation results in a string.
when a projection is used that pushes this concatenation to the database side, the result is unexpected. perhaps the generated query should coalesce the nullable string before concatenating?