使用C#和导航属性查询实体框架

你可以得到 HasCard 从…起 CustomerLockers LockerNumber ;

CustomerLockers = cc.Customer.CustomerLockers

查询;

var myCustomers = (from cc in context.ContractCustomers
    where cc.Contract_ID.Equals(contractID)
    select new
    {
        Licencee = cc.IsLicencee,
        Added = cc.AddedDate,
        Firstname = cc.Customer.FirstName,
        Lastname = cc.Customer.LastName,
        DOB = cc.Customer.DateOfBirth,
        Postcode = cc.Customer.PostCode,
        CustomerNumber = cc.CustomerNumber,
        CustomerLockerHasCard = cc.Customer.CustomerLockers
                        .Where(x => x.LockerNumber == 1000)
                        .Select(x => x.HasCard)
    }
)

此外,我建议您将模型类定义为已知类型,而不是使用匿名类型。

一种选择是获取客户列表,而不仅仅是客户编号:

var myCustomers = (from cc in context.ContractCustomers
where cc.Contract_ID.Equals(contractID)
select new
{
    Licencee = cc.IsLicencee,
    Added = cc.AddedDate,
    Firstname = cc.Customer.FirstName,
    Lastname = cc.Customer.LastName,
    DOB = cc.Customer.DateOfBirth,
    Postcode = cc.Customer.PostCode,
    CustomerNumber = cc.CustomerNumber,
    listOfCustomers = cc.Customer.ToList() // <-Here, a list
}
)

然后可以使用循环:

foreach(var customer in myCustomers.listOfCustomers)
{
    var listOfLockers = customer.CustomerLockers.ToList();
}

但这更像是一种初学者的方式,请记住,最好在一个查询中获取所需的所有内容,如Stormcloack的答案。

这个答案只是为了向你展示你如何用最简单的方法挖掘实体。