Difference Between Select and SelectMany

Question

I\'ve been searching the difference between Select and SelectMany but I haven\'t been able to find a suitable answer. I need to learn the differenc

Answer 1

Without getting too technical - database with many Organizations, each with many Users:-

var orgId = "123456789";

var userList1 = db.Organizations
                   .Where(a => a.OrganizationId == orgId)
                   .SelectMany(a => a.Users)
                   .ToList();

var userList2 = db.Users
                   .Where(a => a.OrganizationId == orgId)
                   .ToList();

both return the same ApplicationUser list for the selected Organization.

The first "projects" from Organization to Users, the second queries the Users table directly.