WHERE IN子句AS对象实体框架

Question

If I have a Company objects :

var companies = db.Companies.Where(...);

And a User objects which related to Company object one-to-many :

var users = db.Users.Where(...);

How I can achieve a criteria like select * from users where user.company in (company)

Reading from some articles, I tried something like :

users.Where(x => companies.Contains(x.company))

But seems doesn't work. What I missed here?

EDIT

Exact Answer :

public PartialViewResult IndexGrid(String search)
{
    var companies = db.Users.Find(User.Identity.GetUserId()).Companies.AsQueryable();
    Guid[] guids = companies.Select(c => c.Id).ToArray();

    if (String.IsNullOrEmpty(search))
        return PartialView("_IndexGrid", db.Set<Quotation>().OrderByDescending(x => x.Code).AsQueryable()
            .Where(x => guids.Contains(x.Company.Id)));
    else
        return PartialView("_IndexGrid", db.Set<Quotation>().OrderByDescending(x => x.Code).AsQueryable()
            .Where(x => guids.Contains(x.Company.Id))
            .Where(x => x.Code.Contains(search)|| x.MasterCustomer.Name.Contains(search)));
}

Answer 1

When you use last variant as

users.Where(x => companies.Contains(x.company))

.Net doesn't know how to compare Companies and uses references to equal objects. Please, try this if your Company has id property. If not, please let me know.

users.Where(x => companies.Select(c => c.Id).Contains(x.company.Id))

Answer 2

I guess you need to select for its IDs:

var companies = db.Companies.Where(...);
var myUsers = db.Users.Where(w=>companies.Select(x=>x.Id).Contains(w.CompanyId)).ToList();

if you have a reference between them both, then you can for example:

var myUsers = db.Users.Include(x=>x.Company)
                   .Where(w=>w.Company != null && w.Company.Name == "MyCompanyName")
                   .ToList();