im using poco code first . how do i get the last insert after savechanges() ?
thanks
I resolve that problem in such way:
with Max() - you can get last id from table
db.Products.Add(product);
db.SaveChanges();
int lastProductId = db.Products.Max(item => item.ProductId);
ProductId is Key() and increment
register = db.registers.CreateObject();
register.id = 0;
register.customer = h.customer;
register.employee = employee_created;
register.created = DateTime.Now;
db.registers.AddObject(register);
db.SaveChanges();
//You can get the ID here
int last_insert_id = register.id;
After you've saved an entity in the context (SaveChanges()). The ID property on the poco itself should be set by the entity framework.
If you actually want more information about the modified entities, you can look for them in the ObjectStateManager provided by the Entity Framework's ObjectContext.
var newProduct = db.Product.Add(model);
db.SaveChanges();
var productId = model.Id;
It automatically adds it to the object you are saving
Refer to the following example -
db.Hotels.Add(hotels);
db.SaveChanges();
var id = hotels.Id;
It worked for me.
Source - https://dzone.com/articles/how-return-id-field-after
Related
I am pretty new to Entity Framework. I am getting an error as
An object with a temporary EntityKey value cannot be attached to an
object context
I think I am doing something wrong.
I have a Customer table and Address table where the Address table has customer's ID as foreign key.
I want to add a new address to the customer entity and keep in session and in next call I want to save it. this is only an example.
using (var db = new MyModel())
{
Customer cust = db.Customers.SingleOrDefault(c => C.ID == 1);
Address addr = new Address();
addr.Street = "123 super st";
cust.Addresses.Add(addr);
Session["customer"] = cust;
}
Customer SessionCustomer = (Customer)Session["customer"];
Customer.Comments = "Added new address";
using (var db = new MyModel())
{
db.Customers.Attach(SessionCustomer); //This throws exception: An object with a temporary EntityKey value cannot be attached to an object context
db.ObjectStateManager.ChangeObjectState(SessionCustomer, System.Data.EntityState.Modified);
db.SaveChanges();
}
Any help is appreciated. thank you.
Try using db.Customers.AddObject() for reattaching object to datacontext.
Take also a look at this: http://msdn.microsoft.com/en-us/library/system.data.objects.objectcontext.addobject.aspx
Cheers
Linq to entity query to delete a specific column from a table by matching a condition`
public ActionResult deleteChecks(string checkValue)
{
check_master checks = (from table in db.check_master
where table.check_code == checkValue
select table).First();
//now how to delete/remove checks.mcheck
return View("Edit");
}`
Only want to update a single column element with null value(of selected row) from the table check_master
You can set a single property (which maps to a column) to null and save it to the database
foreach(check_master check in checks)
{
check.mcheck = null;
}
db.SaveChanges();
using (NorthwindDataContext db = new NorthwindDataContext())
{
// Retrieve the existing entity. Database Call 1
Product product = db.Products.First(p => p.ProductID == 1);
// Change the properties. LINQ to SQL knows
// these specific properties have changed.
product.UnitsInStock = 14;
// Flush the changes. Database Call 2
db.SubmitChanges();
}
Entity framework works with constant table scheme only.
Tell please, what your global aim is, may be there's some more suitable way to do it.
Updated:
foreach(var chm in db.check_master)
{
chm.mcheck = null;
}
db.SaveChanges();
I believe that Linq to Entities only support DML, it does not support DDL operations.
So you would have to use stored procedure or ADO.NET raw query.
EDIT
you can do simple update like this :
public ActionResult deleteChecks(string checkValue)
{
check_master checks = (from table in db.check_master
where table.check_code == checkValue
select table).First();
checks.mcheck = null;
db.SaveChanges();
return View("Edit");
}`
i want to make sure all product names are unique so i tried to do the following.
but it is causing an infinity loop at the lambda expression.
public partial class Product
{
partial void OnProductNameChanging(string value)
{
using(var ctx = new MyEntityContext()){
var val = value;
var item = ctx.Products.Where(o=>o.ProductName == val).FirstOrDefault();
if(item != null)
throw new ValidationException("Product Name existed.");
}
}
}
i'm using asp.net 4.0 with dynamic data and entity framework.
Why don't you set it up on database level and handle exeption in case if product name already exists?
I am not too familiar with EF, but you should get the changeset and compare values. That is, for the Product Entity and in the case of the the changeset having an Update, compare the EXISTING value with NEW, and change the new in the case of duplication.
Here's how to get changeSet in EF :
http://davidhayden.com/blog/dave/archive/2005/11/16/2570.aspx
the comparison and value must be called before any context.SubmitChanges();
Hope this helps.
I am trying to insert the data into 'Order' , 'OrderDetails' tables at the same time. How can I get Auto generated OrderID from the Order table. I am using ADO.NET Entity model.
Thanks..
Use this code:
var order = new Order();
//fill your properties here
var orderDetails = new OrderDetails();
//fill your properties here
orderDetails.Order = order;
db.AddToOrders(order);
db.AddToOrderDetails(orderDetails);
//Save changes
db.SaveChanges();
Hope it will help you with your problem.
I have an ASP.NET Page that updates registered User Address Details for a selected record.
Below is the update method that I am calling from my controller.
When I am calling the ApplyPropertyChanges method, I am getting an error. Did anyone run into the same error while updating the record with Entity Framework?
Appreciate your responses.
Error message:
The existing object in the ObjectContext is in the Added state. Changes can only be applied when the existing object is in an unchanged or modified state.
My Update method:
[HttpPost]
public bool UpdateAddressDetail([Bind(Prefix = "RegUser")] AddressDetail regUserAddress, FormCollection formData)
{
regUserAddress.AD_Id = 3;
regUserAddress.LastUpdated = HttpContext.User.Identity.Name;
regUserAddress.UpdatedOn = DateTime.Now;
regUserAddress.AddressType = ((AddressDetail)Session["CurrentAddress"]).AddressType ?? "Primary";
regUserAddress.Phone = ((AddressDetail)Session["CurrentAddress"]).Phone;
regUserAddress.Country = ((AddressDetail)Session["CurrentAddress"]).AddressType ?? "USA";
miEntity.ApplyPropertyChanges(regUserAddress.EntityKey.EntitySetName, regUserAddress);
miEntity.SaveChanges();
return true;
}
The error is the object is detached from the context, and ApplyPropertyChanges thinks the object is added because it isn't attached. So you would need to query from the data context or get an attached form and then apply the changes then.
HTH.
What Dave Said
+
You need to Attach() the disconnected entity to your object context:
http://msdn.microsoft.com/en-us/library/system.data.objects.objectcontext.attach.aspx
miEntity.Attach(regUserAddress);
miEntity.SaveChanges();
Just add the following code before miEntity.SaveChanges():
miEntity.Entry(regUserAddress).State = EntityState.Modified;
First select the record (object entity), search by key through the ObjectContext. For example if the search ArticleSet EntitySet called for there to record, and once you get it modified its properties with new values and then call SaveChanges() of ObjectContext.
Example:
ObjectQuery<Article> myArt=Context.ArticleSet.Where myArt = (row => row.ArticleId == value);
myArt.Description=" new value ";
etc. ..
etc ...
Context.SaveChanges ();