Question

我需要获取与给定业务和给定联系人代码相关的联系人。联系人可以有多个联系人代码。

这就像我能够得到的一样 - 任何帮助都值得赞赏......

    int bid = 10;

    var sendto = from businesscontact in db.businesscontacts.Where(bus => bus.businessid == bid).Include(bc => bc.contact where contact.contactscontactcodes.contactcodesid.Contains(55)) select r.email;

这是......之后的等效t-sql ...

 SELECT  contacts.email
    FROM   businesscontacts 
    INNER JOIN contacts ON businesscontacts.contactsid = contacts.contactsid 
    INNER JOIN contactscontactcodes ON contacts.contactsid = contactscontactcodes.contactsid 
where contactscontactcodes.contactcodesid = @cid 
AND businesscontacts.businessid = @bid

Answer 1

using(EntityClass entities = new EntityClass())
{
var email = 
      (from biz in entities.BusinessContacts
      where biz.businessid = bid
      from codes in entities.ContactsContactCodes
      where codes.contactcodesid = cid
      from c in entites.Contacts
      where c.contactsid == codes.contactsid && c.contactsid == biz.contactsid
      select c.email).FirstOrDefault();     
}

Answer 2

你可以这样做：

int cid = 1;
int bid = 2;

var sendto = from businesscontact in db.businesscontacts
             join contacts in db.contacts 
             on businesscontact.contactsid equals contacts.contactid
             join contactscontactcodes in db.contactscontactcodes  
             on contacts.contactsid equals contactscontactcodes.contactsid
             where contactscontactcodes.contactcodesid = cid
             && businesscontacts.businessid = bid
             select contact.email;

在fk表上具有多个连接的LINQ查询

2 个答案: