[英]Linq to EF system not supported exception System.NotSupportedException
Scratching my head over this Linq query. 我为这个Linq查询抓狂了。 It's Entity Framework. 它是实体框架。 The query does transformation into different model objects. 该查询确实转换为不同的模型对象。 If I comment or remove the areas of the code that I have indicated as causing the error the linq query works. 如果我注释或删除了指示为导致错误的代码区域,则linq查询有效。 But is seems to me that I should be able to write a query like this with out getting this error: 但是在我看来,我应该能够编写这样的查询而不会出现此错误:
Unable to create a null constant value of type 'DomainModel.Model.CustomerAddress'. 无法创建类型为'DomainModel.Model.CustomerAddress'的空常量值。 Only entity types, enumeration types or primitive types are supported in this context. 在此上下文中仅支持实体类型,枚举类型或原始类型。
Can anyone tell me why I cannot or more importantly what I need to change to make it work? 谁能告诉我为什么我不能或更重要地需要进行更改以使其正常工作?
Thanks 谢谢
var orders = from o in _db.Orders
.Include("User")
.Include("OrderItems.Inventories.Product")
.Include("Transactions")
.Include("CustomerAddressBilling.Address")
.Include("CustomerAddressBilling.Customer")
.Include("CustomerAddressBilling.Contact")
.Include("CustomerAddressShipping.Address")
.Include("CustomerAddressShipping.Customer")
.Include("CustomerAddressShipping.Contact")
.Include("ShippingMethod")
// this works ok
let items = (o.OrderItems.Select(i => new Model.OrderItem
{
OrderItemId = i.OrderItemId,
OrderId = i.OrderId,
DateAdded = i.CreateDate,
LineItemPrice = i.Inventories.Sum(ii => ii.Product.Price),
Product = i.Inventories.FirstOrDefault().Product,
Quantity = i.Inventories.Count()
}))
// this works ok
let transactions = (o.Transactions.Select(t => new Model.Transaction
{
Id = t.TransactionId,
OrderId = t.OrderId,
Amount = t.Amount,
AuthorizationCode = t.AuthorizationCode,
DateExecuted = t.TransactionDate,
Notes = t.Notes,
Processor = (Model.TransactionProcessor)t.ProcessorId
}))
// this causes the error
let cab = o.CustAddBillingId.HasValue ? (new Model.CustomerAddress
{
Id = o.CustomerAddressBilling.CustAddId,
UserName = o.User.UserName,
FirstName = o.CustomerAddressBilling.Customer.FirstName,
LastName = o.CustomerAddressBilling.Customer.LastName,
MiddleInitial = o.CustomerAddressBilling.Customer.MiddleName,
Salutation = o.CustomerAddressBilling.Customer.Salutation,
Suffix = o.CustomerAddressBilling.Customer.Suffix,
Street1 = o.CustomerAddressBilling.Address.Line1,
Street2 = o.CustomerAddressBilling.Address.Line2,
Street3 = o.CustomerAddressBilling.Address.Line3,
City = o.CustomerAddressBilling.Address.City,
StateOrProvince = o.CustomerAddressBilling.Address.State,
Zip = o.CustomerAddressBilling.Address.PostalCode,
Country = o.CustomerAddressBilling.Address.Country,
Latitude = o.CustomerAddressBilling.Address.Lat,
Longitude = o.CustomerAddressBilling.Address.Long,
Email = o.CustomerAddressBilling.Contact.ContactInfo,
IsDefault = o.CustomerAddressBilling.IsPrimary
}) : default(Model.CustomerAddress)
// this causes the error
let cas = o.CustAddShippingId.HasValue ? (new Model.CustomerAddress
{
Id = o.CustomerAddressShipping.CustAddId,
UserName = o.User.UserName,
FirstName = o.CustomerAddressShipping.Customer.FirstName,
LastName = o.CustomerAddressShipping.Customer.LastName,
MiddleInitial = o.CustomerAddressShipping.Customer.MiddleName,
Salutation = o.CustomerAddressShipping.Customer.Salutation,
Suffix = o.CustomerAddressShipping.Customer.Suffix,
Street1 = o.CustomerAddressShipping.Address.Line1,
Street2 = o.CustomerAddressShipping.Address.Line2,
Street3 = o.CustomerAddressShipping.Address.Line3,
City = o.CustomerAddressShipping.Address.City,
StateOrProvince = o.CustomerAddressShipping.Address.State,
Zip = o.CustomerAddressShipping.Address.PostalCode,
Country = o.CustomerAddressShipping.Address.Country,
Latitude = o.CustomerAddressShipping.Address.Lat,
Longitude = o.CustomerAddressShipping.Address.Long,
Email = o.CustomerAddressShipping.Contact.ContactInfo,
IsDefault = o.CustomerAddressShipping.IsPrimary
}) : default(Model.CustomerAddress)
// this causes the error
let sm = o.ShippingMethodId.HasValue ? (new ShippingMethod
{
Id = o.ShippingMethod.ShippingMethodId,
Carrier = o.ShippingMethod.Carrier,
ServiceName = o.ShippingMethod.ServiceName,
BaseRate = o.ShippingMethod.BaseRate,
RatePerPound = o.ShippingMethod.RatePerPound,
DaysToDeliver = o.ShippingMethod.DaysToDeliver,
EstimatedDelivery = o.ShippingMethod.EstimatedDelivery
}) : default(ShippingMethod)
select new Model.Order
{
Id = o.OrderId,
UserName = o.User.UserName,
DateCreated = o.CreateDate,
Items = items.AsQueryable(),
Transactions = transactions.AsQueryable(),
ShippingAddressId = o.CustAddShippingId,
BillingAddressId = o.CustAddBillingId,
// have to comment these next 3 lines as well
ShippingAddress = cas,
BillingAddress = cab,
ShippingMethod = sm,
// to here
UserLanguageCode = "en",
DateShipped = o.ShippedDate,
EstimatedDelivery = o.EstimatedDelivery,
TrackingNumber = o.TrackingNumber,
TaxAmount = o.TaxAmount,
DiscountReason = o.DiscountReason,
DiscountAmount = o.DiscountAmount
};
Ok, I have figured this out. 好的,我知道了。 The problem is the database allows null forien keys to those related entities, I changed the database so the forien keys were not nullable and updated the model from the database. 问题是数据库允许对那些相关实体使用空的Forien键,我更改了数据库,以使Forien键不可为空,并从数据库更新了模型。 I created new data enties that represented non-ShippingMethods electronic, and in-person, and also have in-person CustomerAddress so I can have links to data that represents not only that I don't have the data but why I don't have the data. 我创建了新的数据实体,这些实体代表非电子方式的和面对面的非ShippingMethods,并且还具有面对面的CustomerAddress,因此我可以链接到数据,这些数据不仅代表我没有数据,还代表为什么我没有数据数据。
public IQueryable<Model.Order> GetOrders()
{
var orders = from o in _db.Orders
.Include("User")
.Include("OrderItems.Inventories.Product")
.Include("Transactions")
.Include("CustomerAddressBilling.Address")
.Include("CustomerAddressBilling.Customer")
.Include("CustomerAddressBilling.Contact")
.Include("CustomerAddressShipping.Address")
.Include("CustomerAddressShipping.Customer")
.Include("CustomerAddressShipping.Contact")
.Include("ShippingMethod")
let items = (o.OrderItems.Select(i => new Model.OrderItem
{
OrderItemId = i.OrderItemId,
OrderId = i.OrderId,
DateAdded = i.CreateDate,
LineItemPrice = i.Inventories.Sum(ii => ii.Product.Price),
Product = i.Inventories.FirstOrDefault().Product,
Quantity = i.Inventories.Count()
}))
let transactions = (o.Transactions.Select(t => new Model.Transaction
{
Id = t.TransactionId,
OrderId = t.OrderId,
Amount = t.Amount,
AuthorizationCode = t.AuthorizationCode,
DateExecuted = t.TransactionDate,
Notes = t.Notes,
Processor = (Model.TransactionProcessor)t.ProcessorId
}))
let cab = new Model.CustomerAddress
{
Id = o.CustomerAddressBilling.CustAddId,
UserName = o.User.UserName,
FirstName = o.CustomerAddressBilling.Customer.FirstName,
LastName = o.CustomerAddressBilling.Customer.LastName,
MiddleInitial = o.CustomerAddressBilling.Customer.MiddleName,
Salutation = o.CustomerAddressBilling.Customer.Salutation,
Suffix = o.CustomerAddressBilling.Customer.Suffix,
Street1 = o.CustomerAddressBilling.Address.Line1,
Street2 = o.CustomerAddressBilling.Address.Line2,
Street3 = o.CustomerAddressBilling.Address.Line3,
City = o.CustomerAddressBilling.Address.City,
StateOrProvince = o.CustomerAddressBilling.Address.State,
Zip = o.CustomerAddressBilling.Address.PostalCode,
Country = o.CustomerAddressBilling.Address.Country,
Latitude = o.CustomerAddressBilling.Address.Lat,
Longitude = o.CustomerAddressBilling.Address.Long,
Email = o.CustomerAddressBilling.Contact.ContactInfo,
IsDefault = o.CustomerAddressBilling.IsPrimary
}
let cas = new Model.CustomerAddress
{
Id = o.CustomerAddressShipping.CustAddId,
UserName = o.User.UserName,
FirstName = o.CustomerAddressShipping.Customer.FirstName,
LastName = o.CustomerAddressShipping.Customer.LastName,
MiddleInitial = o.CustomerAddressShipping.Customer.MiddleName,
Salutation = o.CustomerAddressShipping.Customer.Salutation,
Suffix = o.CustomerAddressShipping.Customer.Suffix,
Street1 = o.CustomerAddressShipping.Address.Line1,
Street2 = o.CustomerAddressShipping.Address.Line2,
Street3 = o.CustomerAddressShipping.Address.Line3,
City = o.CustomerAddressShipping.Address.City,
StateOrProvince = o.CustomerAddressShipping.Address.State,
Zip = o.CustomerAddressShipping.Address.PostalCode,
Country = o.CustomerAddressShipping.Address.Country,
Latitude = o.CustomerAddressShipping.Address.Lat,
Longitude = o.CustomerAddressShipping.Address.Long,
Email = o.CustomerAddressShipping.Contact.ContactInfo,
IsDefault = o.CustomerAddressShipping.IsPrimary
}
let sm = new ShippingMethod
{
Id = o.ShippingMethod.ShippingMethodId,
Carrier = o.ShippingMethod.Carrier,
ServiceName = o.ShippingMethod.ServiceName,
BaseRate = o.ShippingMethod.BaseRate,
RatePerPound = o.ShippingMethod.RatePerPound,
DaysToDeliver = o.ShippingMethod.DaysToDeliver,
EstimatedDelivery = o.ShippingMethod.EstimatedDelivery
}
select new Model.Order
{
Id = o.OrderId,
UserName = o.User.UserName,
DateCreated = o.CreateDate,
Items = items.AsQueryable(),
Transactions = transactions.AsQueryable(),
ShippingAddressId = o.CustAddShippingId,
BillingAddressId = o.CustAddBillingId,
ShippingAddress = cas,
BillingAddress = cab,
ShippingMethod = sm,
UserLanguageCode = "en",
DateShipped = o.ShippedDate,
EstimatedDelivery = o.EstimatedDelivery,
TrackingNumber = o.TrackingNumber,
TaxAmount = o.TaxAmount,
DiscountReason = o.DiscountReason,
DiscountAmount = o.DiscountAmount
};
return orders;
}
And no errors! 而且没有错误!
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.