Question

My code:

i f(!string.IsNullOrWhiteSpace(gender))
    if (gender == "NULL")
        predicate = predicate.And(x => string.IsNullOrWhiteSpace(gender));
    else
        predicate = predicate.And(x => x.Gender == gender);

When gender is NULL and when I am executing the flowing line:

var filteredUsers = _personExtendedRepository.GetMany(predicate).ToList();

an error occurs:

“LINQ to Entities does not recognize the method ‘Boolean IsNullOrWhiteSpace(System.String)’ method, and this method cannot be translated into a store expression.”

Note:
When I am executing the following line in SQL Server Management Studio:

SELECT * FROM UVW_Sample WHERE Gender IS NULL

Records are displaying. Please help how to solve this issue.

Answer 1

string.IsNullOrWhiteSpace cannot be translated into SQL, so if you want to check whether column is null use something like:

predicate = predicate.And(x => x.Gender == null);