Question

I’ve figured out how to do conditional queries with linq to sql and I’ve also figured out how to OR where clauses. Unfortunately I can’t figure out how to do both at once. I can do a conditional where clause something like:

var ResultsFromProfiles = from AllPeeps in SearchDC.aspnet_Users
                          select AllPeeps;


if (SearchFirstNameBox.Checked)
{
    ResultsFromProfiles = ResultsFromProfiles.Where(p => p.tblUserProfile.FirstName.Contains(SearchTerm));
}

if (SearchLastNameBox.Checked)
{
    ResultsFromProfiles = ResultsFromProfiles.Where(p => p.tblUserProfile.LastName.Contains(SearchTerm));
}

This will get me any profiles where the first name AND the last name contain the search term.

Or I could do:

var ResultsFromProfiles = from p in SearchDC.aspnet_Users
                          where p.tblUserProfile.LastName.Contains(SearchTerm) ||
                                p.tblUserProfile.FirstName.Contains(SearchTerm)
                          select p;

This would get me any profiles where the first name OR the last name contains the search term.

I have a bunch of checkboxes where the user can specify which fields they want to search for teh search term, so I want to be able to build a query that will conditionally add them as in the first code snippet above, but add them as an OR so they work like the second snippet. That way it will search for any matches anywhere in the specified fields.

Any tips?

Answer 1

Yeah, use PredicateBuilder. It lets you build up dynamic queries with And or Or semantics. It’s free and stable- I use it all over the place.