I have a two table products and categories. When I add a product to products, I get an error. I share the codes.
class Products
{
public int Id { get; set; }
public string Name { get; set; }
public float Price { get; set; }
public string Description { get; set; }
public int CategoryId { get; set; }
public string CategoryName { get; set; }
public Categories Category { get; set; }
}
With this method, I get the products. After I fill a datagridview. But I want to see categoryName instead of CategoryId. It works, I see the categoryName instead of CategoryId in datagridview.
public List<Products> GetProducts()
{
var products = context.Products.Include(x =>x.Category ).Select(m => new Products()
{
Id = m.Id,
Name = m.Name,
Price = m.Price,
Description = m.Description,
CategoryName=m.Category.Name
}).ToList();
return products;
}
After that I have an Add method
public void AddProduct(Products products )
{
context.Products.Add(products);
context.SaveChanges();
}
However, when I try to add a new product, I have an error.
The issue is that Category Name is not in the physical table, just your object. So when EF attempts to generate the SQL, it can't find a column called CategoryName.
Take a look at this question
Exclude Property on Update in Entity Framework
Related
I am trying to add a value in my checkoutItems table, in the checkoutItems repository I use this method:
public async Task AddItemAsync(unitItem item, int amount, string selectedOptions)
{
var checkoutItem = await _appDbContext.CheckoutItems.SingleOrDefaultAsync(s => s.unitItem.unitItemId == item.unitItemId && s.CheckoutId == _checkout.CheckoutId);
if (checkoutItem == null)
{
checkoutItem = new CheckoutItem
{
CheckoutId = _checkout.CheckoutId,
unitItem = item,
Amount = 1,
selectedOptions = selectedOptions
};
await _appDbContext.CheckoutItems.AddAsync(checkoutItem);
}
else
{
checkoutItem.Amount++;
}
await _appDbContext.SaveChangesAsync();
}
But when this method tries to save the changes I get an error.
SqlException: Cannot insert explicit value for identity column in table 'Categories' when IDENTITY_INSERT is set to OFF
The issue is I am not trying to insert a value in the Categories table. When I check the SQL Server Profiler I see this code is trying to be executed:
exec sp_executesql N'SET NOCOUNT ON;
INSERT INTO [Categories] ([CategoryId], [CategoryName], [Description])
VALUES (#p0, #p1, #p2);
',N'#p0 int,#p1 nvarchar(450),#p2 nvarchar(4000)',#p0=3,#p1=N'Food',#p2=N'Food served by our kitchen'
I have no idea where this is coming from. Everything was working fine until recently. I made no changes to the code and even restored the database to an earlier state to remove the changes (if any) I had made on the database, but no luck. What is causing this and how can I fix it.
The checkoutItems model looks like this:
public class CheckoutItem
{
public int CheckoutItemId { get; set; }
public unitItem unitItem { get; set; }
public int Amount { get; set; }
public string CheckoutId { get; set; }
public string selectedOptions { get; set; }
}
And there are 2 degrees of separation between a checkoutItem and Category where an Item has a category.
Edit
If you comment out the line unitItem = item, in the add AddItemAsync method, seems to go around the issue. So the issue seems to be around adding the unitItem.
I still don't understand why it is adding a category when add a checkout item. The model for the unitItem looks like this:
public class unitItem
{
[Required]
public int unitItemId { get; set; }
[Required]
public string Name { get; set; }
[DisplayFormat(DataFormatString = "{0:n2}")]
public decimal Price { get; set; }
public bool InStock { get; set; }
public DateTime DateModified { get; set; }
public int CategoryId { get; set; }
[Required]
public virtual Category Category { get; set; }
public string ImageUrl { get; set; }
public string Description { get; set; }
public string OptionFormData { get; set; }
}
in your unitItem class add Required attribute to CategoryId not Category
public class unitItem
{
[Required] //here
public int CategoryId { get; set; }
//[Required] //not here
public virtual Category Category { get; set; }
....
then in AddItemAsync method; set NULL category object if CategoryId is bigger than zero
public async Task AddItemAsync(unitItem item, int amount, string selectedOptions)
{
item.Category = null; //be sure item.CategoryId is not zero
.....
I have two documents Ticket and MenuItem i have created index with TransformResults but problem is i am getting null value for Loaded document in transform
public class Ticket
{
public int ID { get; set; }
public int ItemId { get; set; }
public string ItemName { get; set; }
public int Price { get; set; }
}
public class MenuItem
{
public int ID { get; set; }
public string ItemName { get; set; }
public string PriceCategory { get; set; }
}
i have created a index like
public class TicketItemGross : AbstractIndexCreationTask<Ticket, TicketItemGross.TicketItemDetails>
{
public class TicketItemDetails
{
public string ID { get; set; }
public string ItemId { get; set; }
public string ItemName { get; set; }
public int Price { get; set; }
public string PriceCategory { get; set; }
}
public TicketItemGross()
{
Map = docs => from doc in docs
select new
{
ID = doc.ID,
ItemId=doc.ItemId,
ItemName=doc.ItemName,
Price=doc.Price
};
TransformResults = (database, docs) => from m in docs
let d = database.Load<MenuItem>(m.ID)
select new
{
ID = m.ID,
ItemId = m.ItemId,
ItemName = m.ItemName,
Price = m.Price,
PriceCategory=d.PriceCategory
};
}
}
and the problem is that when i query data. I get null for PriceCategory but for all other fields i get correct value
here is query
IEnumerable<TicketItemGross.TicketItemDetails> list;
using (var session = store.OpenSession())
{
list = session.Query<TicketItemGross.TicketItemDetails, TicketItemGross>();
}
This is happening because you are using integer IDs. When you call database.Load in your transform, you'll need to manually convert it to a string ID.
database.Load<MenuItem>("MenuItems/" + m.ID)
This is one of several places where Raven gets confused if you use integer or guid IDs. If you use string ids, you won't have this problem.
Also, you might consider using a results transformer instead. They are easier than index transformers, which are now obsolete.
I have these two classes
[ActiveRecord("Customers", Lazy=true)]
public class Customer : ActiveRecordBase<Customer>
{
[PrimaryKey(PrimaryKeyType.Identity, Access = PropertyAccess.AutomaticProperty)]
public virtual int Id { get; private set; }
[Property]
public virtual string Name { get; set; }
[HasMany(Lazy = true)]
public virtual IList<Order> Orders { get; set; }
}
[ActiveRecord("Orders", Lazy=true)]
public class Order : ActiveRecordBase<Order>
{
[PrimaryKey(PrimaryKeyType.Identity, Access = PropertyAccess.AutomaticProperty)]
public virtual int Id { get; private set; }
[Property]
public virtual string Product { get; set; }
[BelongsTo(Lazy = FetchWhen.OnInvoke)]
public virtual Customer Customer { get; set; }
}
I want to select all orders and foreach of them, get the id of the customer.
So I do this:
using (new SessionScope())
{
var orders = Order.FindAll();
foreach (var o in orders)
{
int id = o.Customer.Id;
}
}
It works, but it creates a SELECT phrase for each call to o.Customer.Id.
Now, the Order already has the Id of the customer, so how can I get it without revisiting the database??
the following code should allow you to get the id (but I couldn't test it at the moment):
int id = (int)((INHibernateProxy)order.Customer).HibernateLazyInitializer.Identifier;
Greetings
Juy Juka
I am trying to select from a list of categories where it matches the category type of a list of items using linq. IE, from a list of all the FIGstationeryCategories, select only the ones where the FiGStationeryType has a matching category from an already filtered list. The models are listed below.
public class FIGstationeryType
{
public int Id { get; set; }
public virtual FIGstationeryCategory Category { get; set; }
public virtual FIGcompany Company { get; set; }
public decimal Height { get; set; }
public decimal Width { get; set; }
public virtual FIGstationeryType Template { get; set; }
public bool DoubleSided { get; set; }
}
public class FIGstationeryCategory
{
public int Id { get; set; }
public string Name { get; set; }
public decimal MaxZoom { get; set; }
public ICollection<FIGstationeryType> StationeryItems { get; set; }
}
I have been going around in circles with this, and any help will be much appreciated. I haven't got very far! The first line of code works fine, it is the second one I am struggling with.
var listOfItems = db.StationeryTypes
.Where(C => C.Company.Users.Any(u => u.UserId == WebSecurity.CurrentUserId))
.ToList();
var categoryList = db.StationeryCategories
.Where(listOfItems
Any help would be much appreciated.
var listOfCategories =
(from o in listOfItems select o.Category.Name).Distinct().ToList();
When I thought about it (After watching 3 hours of linq videos last night), I realised that the listOfItems already held all the categories which where in use, so I didn't need to query and compare the two tables, just draw the relevant values from the list I already had.
I am not entirely sure how you want to select your categories but this probably goes a little way:
var categoryList = db.StationeryCategories
.*Select*(x => listOfItems.Where(y => y.Category == x)
.FirstOrDefault());
Can you clarify if this is the criteria you are after?
I'm trying to use the TransformResults feature, and I can't get it to work. I'm not totally sure I understand this feature, perhaps there is another way to solve this problem. What I want is just the Id from the Order and the email addesses from the Customer and the Entrepreneur. I am happy for all tips that can take me in the right direction. Here is my code.
Document
public class OrderDocument
public string Id {get; set }
public EntrepreneurInfo EntrepreneurInfo { get; set; }
public CustomerInfo CustomerInfo { get; set; }
public OrderStatus CurrentOrderStatus { get; set; }
}
Info classes
public class EntrepreneurInfo
{
public string EntrepreneurDocumentId { get; set; }
public string Number { get; set; }
public string Name { get; set; }
}
public class CustomerInfo
{
public string CustomerDocumentId { get; set; }
public string Number { get; set; }
public string Name { get; set; }
}
The info classes are just subsets of a Customer and Entrepreneur documents respectively.
The Customer and Entrepreneur documents inherits from a base class ( AbstractOrganizationDocument) that has the EmailAddress property.
My Index
public class OrdersApprovedBroadcastingData :
AbstractIndexCreationTask<OrderDocument, OrdersApprovedBroadcastingData.ReduceResult>
{
public OrdersApprovedBroadcastingData()
{
this.Map = docs => from d in docs
where d.CurrentOrderStatus == OrderStatus.Approved
select new
{
Id = d.Id,
CustomerId = d.CustomerInfo.CustomerDocumentId,
EntrepreneurId = d.EntrepreneurInfo.EntrepreneurDocumentId
};
this.TransformResults = (db, orders) => from o in orders
let customer = db.Load<CustomerDocument>(o.CustomerId)
let entrepreneur = db.Load<EntrepreneurDocument>(o.EntrepreneurId)
select
new
{
o.Id,
o.CustomerId,
CustomerEmail = customer.EmailAddress,
o.EntrepreneurId,
EntrepreneurEmail = entrepreneur.EmailAddress
};
}
public class ReduceResult
{
public string Id { get; set; }
public string CustomerId { get; set; }
public string CustomerEmail { get; set; }
public string EntrepreneurId { get; set; }
public string EntrepreneurEmail { get; set; }
}
}
If I look at the result of this Index in Raven Studio I get null values for all fields except the Id. And finally here is my query.
Query
var items =
this.documentSession.Query<OrdersApprovedBroadcastingData.ReduceResult, OrdersApprovedBroadcastingData>()
.Select(x => new OrdersToBroadcastListItem
{
Id = x.Id,
CustomerEmailAddress = x.CustomerEmail,
EntrepreneurEmailAddress = x.EntrepreneurEmail
}).ToList();
Change your index to:
public class OrdersApprovedBroadcastingData : AbstractIndexCreationTask<OrderDocument>
{
public OrdersApprovedBroadcastingData()
{
Map = docs => from d in docs
where d.CurrentOrderStatus == OrderStatus.Approved
select new
{
};
TransformResults = (db, orders) =>
from o in orders
let customer = db.Load<CustomerDocument>(o.CustomerInfo.CustomerDocumentId)
let entrepreneur = db.Load<EntrepreneurDocument>(o.EntrepreneurInfo.EntrepreneurDocumentId)
select new
{
o.Id,
CustomerEmailAddress = customer.EmailAddress,
EntrepreneurEmailAddress = entrepreneur.EmailAddress
};
}
}
Your result class can simply be the final form of the projection, you don't need the intermediate step:
public class Result
{
public string Id { get; set; }
public string CustomerEmailAddress { get; set; }
public string EntrepreneurEmailAddress { get; set; }
}
You don't have to nest this class in the index if you don't want to. It doesn't matter either way. You can query either with:
var items = session.Query<Result, OrdersApprovedBroadcastingData>();
Or with
var items = session.Query<OrderDocument, OrdersApprovedBroadcastingData>().As<Result>();
Though, with the first way, the convention tends to be to nest the result class, so really it would be
var items = session.Query<OrderDocument.Result, OrdersApprovedBroadcastingData>();
Note in the index map, I am not including any properties at all. None are required for what you asked. However, if you want to add a Where or OrderBy clause to your query, any fields you might want to filter or sort on should be put in there.
One last thing - the convention you're using of OrderDocument, CustomerDocument, EntrepreneurDocument, is a bit strange. The usual convention is just Order, Customer, Entrepreneur. Think of your documents as the persisted form of the entities themselves. The convention you are using will work, it's just not the one usually used.