下面的表达式返回了一个联系人-带有数十个属性的整个联系人。虽然这很好,但是理想情况下,我希望仅返回联系人的Id (contact.contactId) 属性。我该怎么做?
var assocOrg = Contacts.Where(x => x.ContactTypeID == 2 && x.OrganizationName == "COMPANY XYZ");
var result = Contacts.Where(x => ...)
.Select(x => x.ContactID);
或者var result = from x in Contacts
where x.ContactTypeID == 2 && x.OrganizationName == "COMPANY XYZ"
select x.ContactID;
如果您想获取与您的条件匹配的单个或第一个对象,请使用以下方法:
var result = Contacts.Where(x => ...)
.Select(x => x.ContactID).FirstOrDefault();
var result = Contacts.Where(x => ...)
.Select(x => x.ContactID).FirstOrDefault();
var assocOrg = Contacts.
Where(x => x.ContactTypeID == 2 && x.OrganizationName == "COMPANY XYZ").
Select(x => x.contactId);
var assocOrg = Contacts.Where(x => x.ContactTypeID == 2 && x.OrganizationName == "COMPANY XYZ").Select(x=> x.contactId).FirstOrDefault();
var assocOrg = Contacts.Where(x => x.ContactTypeID == 2 && x.OrganizationName == "COMPANY XYZ").Select(x=> x.contactId);
var assocOrg = from contact in Contacts
where contact.ContactTypeId == 2 && contact.OrganizationName == "COMPANY XYZ"
select contact.ContactId;