I have created a .edmx for the northwind database. When I run the following statement, the correct number of detail records are retrieved and I can access the detail fields, but how do I access the order header record to view OrderDate, ShipAddress, etc...?
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I am new to Entity Framework and working my way through it little by little. I think I have it figured out on how to get data into and out of 1 table at a time now the challenge is 2 tables into a gridview.
I have a user table that has a list of threads that a user can mark to track. Easy enough. Assign the userid number & threadid to a table with a push button while the user is logged in and viewing any of the posts that are on that thread. The new challange is to get only the posts that the user has marked to track. SQL easy. Entity not sure what to do.
If I make a view or stored procedure and add it to the database that would be an extra step. To join the 2 tables as in sql Select posts from posts where track.userid = @userid join track on post.userid=track.userid Seems Entity was made to avoid this type of thing. Than once the data is gathered I need to bind it to a gridview()
Quite a common use case, it seems, is when re-populating an object from a form is to go
myobj.Name = "textbox value";
myobj.Content = "textbox content";
But, name may not have changed, it may only be a change to the content textbox.
The problem is that entity framework treats Name as changed just because I've set it's value, regardless of whether I've set exactly the same value or not.
Ideally, I would like EF to only mark things as changed if they genuinely have changed.
I have two tabels as mentioned below. I am using entity framework and vs2010.I am not able to write linq query to get data from both the tables. there is one to many relationship(for one category ther can be multiple articles).
View 1 RepliesI need to dynamically access some SQL tables hopefully using the Entity Framework. Here's some pseudo code:
var Account = DB.Accounts.SingleOrDefault(x => x.ID == 12345);
which will return me an Account object and this contains some fields called "PREFIX", "CAMPAIGN ID" and further information about the accounts are stored in separate SQL tables with the naming convention of PREFIX_CAMPAIGNID_MAIN.
The tables all have the same fields so I was thinking of creating a new Entity that isn't mapped anywhere and then dynamically loading it, like so:
var STA01_MAIN = new MyAccount(); // my "un-mapped" entity
DB.LoadTable('STA01_MAIN').LoadInto(STA01_MAIN);
I can now get anything about the STA01_MAIN account: STA01_MAIN.AccountId. So my question is: how do I access these tables using the Entity Framework?
I have a question about Entity Framework. answer if you know answer on this. I have such query :
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Particularly I want to join few tables in one query, but I can NOT use LINQ and can NOT use ObjectQuery with objects mapped to DB fields inside my query. Because each entity creates dynamically. So this is what i
can NOT use : [URL]
The question is can I use something like this instead of using objects?
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The purpose is to use Join method of ObjectQuery with syntax as in Where method :[URL]
A relative newcomer to .net MVC2 and the entity framework, I am working on a project which requires a single web application, (C# .net 4), to connect to multiple different databases depending on the route of access, (ie subdomain).
No problem with this in principle and all the logic is written to transform the subdomain into an entity connection and pass this through to the Entity Model.
The problem comes with the fact that the different database whilst being largely similar in structure contain 3 or 4 unique tables bespoke to that instance.
To my mind there are two ways to solve this issue, neither of which i am sure will be possible.
1/ Use a separate entity model for each database. -Attempts down this route have through up conflicts where table/sp names are the same across differnt db's, or implicit conversion errors when I try and put the different models in different namespaces. or
2/ Overwrite the classes which refer to the changeable database objects based on the value of a base controller property.
My question is if either of theser routes can ever work in principle or if i should just give up on the EF and connect to the dtabases directlky using ADO. Perhaps there is another way to solve this problem i haven't thought of?
I developed and entity framework (.edmx) application in 4.0 in that i got all the data of my querying table and its foreign key referenced tables data also. but when i change my project to 3.5 i am unable to get the data of foreign key referenced tables data.
View 2 RepliesI am working with VS 2010, Entity framework, SQl-Server 2005, ASP.Net web forms. Currently, I am working on the Data access layer library which soon will be a web service, using Entity Framework collaboration with different design patterns like repository pattern and some best practices that posts in different blogs. I am also test each repository using the Unit testing project. Thumbs up! Working fine.
The thing I am worried about is, how much is good for retrieving data from a table that can contain 80-100k records ?
my application have two tables. TableA and TableB TableA have one record
ID StudentName Age
1 MARK 20
I use selectlist to select StudentName .
ViewData["StudentName"] = new SelectList(_db.StudentSet.ToList(), "StudentName", "StudentName");
and then add to TableB. for this case , for me is success, but I also want to add the"Age" into TableB on same time. I don't know how to do it.
I set up Entity Framework for my Table and Stored Procedure to return data. Created a Domain Class as well.
In Domain Class, I am returning Objects as collection.
On .Aspnet page when I drop a Control(Combo,Dropdown) I can set up the source for the controls visually if the source is table.
However, In domain class I have stored precedure object that return collection of data And I cant not set up visually from Designer, I am only available to write code behind. is it possibble that i can set up from desingner.
CAN we use Entity framework in web services.I the following error while the code connects to the database using entity framework
View 3 RepliesI have a sql server database that includes the field ArticleID of type uniqueidentifier that is a primary key and is set to be auto-generated by the database when a new article is added.If i generate my entity model and do the following code:
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Then a new article is saved to the database but the entity framework must be generating a new blank Guid and saving that to the database rather than allowing it to be auto generated as the articleid that shows up saved is all 0.How can i get the Entity Framework to let the Database generate the ArticleId?
Adding data into kartlar table (RehberID,KampanyaID,BrimID) is ok. But which Kart'ID created? I need to learn which Id created after adding data (RehberID,KampanyaID,BrimID) into Kartlar?
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How can I do that? I want to get data from Kartlar which data I added?
i joined together more than one entity: Customer, Personel etc. i used inner join structures. if i look adonet entity framework ,5 entities are generated. i need to run this SP in C# side:
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LOOK BELOW PİC : you can understand it :
MY C# codes: [Code]....
How can i get all joined data from sql with using randevu.GetRandevular(customerID
I have 3 tables User, role and UserInRole THe entity frame work made entities for User and Role and I have successfully made a join with the user and role entities using user.add(role); but I can't seem to get it to remove the link (I want to retain the user and role just remove their association).
using (ProviderEntities context = new ProviderEntities())
{
User u = context.User
.Where(n => n.ApplicationName == application)
.Where(n => n.Username == username).First();
Roles r = context.Roles
.Where(n => n.ApplicationName == application)
.Where(n => n.RoleName == roleName)
.First();
r.User.Remove(u);
context.SaveChanges();
}
The oposite worked when I did r.User.Add(u); but it wont let me now remove it after it been created. Driving me mad as I can't see where I have gone wrong.
I transfered my data from MDF files to MS SQL Database, but I can't get it working with entity framework.
My Old connection string is:
metadata=res://*/Models.EntityModel.csdl|res://*/Models.EntityModel.ssdl|res://*/Models.EntityModel.msl;provider=System.Data.SqlClient;provider connection string="Data Source=.SQLEXPRESS;AttachDbFilename=|DataDirectory|TripsDB.mdf;Integrated Security=True;User
Instance=True;MultipleActiveResultSets=True"
I put all data from TripsDB.mdf to Trips table in local MS SQL 2008 Enterprise database. Also changed connection string to:
Server=WIESIEK;Database=Trips;Trusted_Connection=True;providerName=System.Data.SqlClient;User ID=Jan J. Roman
But my application throws System.ArgumentExceptio with message: The 'server' keyword is not supported.
on line:
private TripsDBEntities2 _entity = new TripsDBEntities2();where TripsDBEntities2 is Entity Framework instance.
I have a stored procedure that generates a float value. I've added the stored procedure to my edmx file and created a function import, but the function isn't showing up in the object browser or via intellisense.
I'm using Visual Studio 2010 and I've verified that the stored procedure works in SSMS. Here is the current stored proc I'm using:
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CarType
Id - PK
Name
CarDetail
Id - PK
TypeId - FK to CarType
I have this simple example here and I want to insert a new CarDetail into the database but for some reason I cannot get the EntityKey to work in EF4 and Framework4 beta 2.
If i declare the following
car_detail.CarTypeReference.EntityKey = new System.Data.EntityKey("MyDB.CarType", "Id", 1)
Each time i try to call SaveChanges, it throws a INSERT constraint error saying that there is a conflict between CarType and CarDetail with the FK. It just seems like the hard coded 1 for CarType is NOT being passed through but instead the default value of 0. What is going on?
If i call car_detail.TypeId = 1 then it works fine with the INSERT.
Why doesn't the EntityKey method work?
how to do this query in EF1:
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I created two stored procedures in SQL Server Management Studio.
First procedure add field in ProjcetsToUsers table (for many-to-many associations)
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I can delete the user from the project and then add another, and the new one is added but removed the remains.
As for data base both this function work correctly.
public void saveOptionalCourses( ArrayList coursesAdded, int studentID)
{
StudentOptionalCoursesXRef XRefObject = new StudentOptionalCoursesXRef();
using (var EntityObject = new SchoolProjectEntities2())
{
foreach ( string list in coursesAdded)
{
XRefObject.StudentDetails = EntityObject.StudentDetails.Where(c => c.StudentID == studentID).First();
XRefObject.OptionalCourses = EntityObject.OptionalCourses.Where(c => c.OptionalCourseName == list).FirstOrDefault();
EntityObject.AddToStudentOptionalCoursesXRef(XRefObject);
}
EntityObject.SaveChanges();
}
with this above method and could save only last row that am returning remaining rows are iterated but are not saving on to database
I'm using the linq to entity command to perform a record update. I want to set one of the fields back to NULL but I'm not sure how do it. I have a query such as
Dim record = From r in db.LISTS where r.ID = refID Select r
record.Title = txtTitle.text
if txtDetail.text = "" then
record.Detail =
end if
I am just getting started with entity framework with asp.net 3.5 using VS 2008
There are two tables, Categories & Subcategories:
Category table: CID, CategoryName Sub Category table: SID, CID, SubCategoryName I would like to get SID, CID, CategoryName, SubCategoryName in the gridview. Just as we write a select statement i.eSelect a.sid, b.cid, b.categoryname, b.subcategoryname from subcategories a inner join categories b on a.cid=b.cid & put the same in a gridview.
I was trying for the whole day & couldnt get atleast one url that would teach how to do it.
I want to insert username and password into two tables (say table1 as well as table 2) using stored procedure.
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