Question

I have a following method:

public IQueryable<Profile> FindAllProfiles(string CountryFrom, string CountryLoc)
{


    return db.Profiles.Where(p => p.CountryFrom.CountryName.Equals(CountryFrom,StringComparison.OrdinalIgnoreCase));

}

Right now, it just filters by CountryFrom but I need to filter it by CountryLoc as well.
So how do I modify the Where filter?

Also, CountryFrom could be null or CountryLoc could be null. So how do I modify the method’s signature to all the nullable input string parameter.

I know how to do this in SQL but I am not sure about lambda expressions or LINQ.

Thanks

Answer 1

Your question isn’t actually LINQ-specific. You can put any boolean conditions inside the lambda that you want, such as:

p => p.CountryFrom.CountryName.Equals(...) && p.CountryLoc.CountryName.Equals(...)

To handle null values you can use the static string.Equals method instead, like this:

p => string.Equals(p.CountryFrom.CountryName, CountryName, StringComparison.OrdinalIgnoreCase)

If this starts getting too long you could always extract it into a method.