My setup is this; first I'm defining a couple of new rows.
newCompany = new company
companyInfo = value.company_info,
companyName = value.company_name,
organizationNumber = value.company_orgnr
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I have a stupid problem with the Entity Framework. I get the following Exception:
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I have an entity with a 4 fields representing the primary key. I copy it via serialization (works fine). I set the old entity to not valid (Datefield set to a date in the past, this field is part of the PK) and set the copied entity to DateTime.Now.Date. When I call context.AddObject I get the Exception above. I tried copying the entity via reflection but the entity has 3-4 references. And when copied, I get another Exception before even Adding the entity to the context. I also tried setting newObj.EntityKey = null and reset all the fields neccessary for the PK. I just want a whole copy of an entity with a different primary key (and some other fields changed too) and Create it in the database.
I have a web form in asp.net. I load the data on the page using EF4 and a foreach. Now it is time to save that data. What is the best way to do that using a postback?
View 1 RepliesI have a one-to-one relationship on two tables with are represented by 2 classes in my EDM. I am trying to save a new record and am confused how to save to the second entity. I have tried the following.
Dim myObject as new MyObject
myObject.prop1 = 5
myObject.prop2 = "Test"
myObject.myOtherObject.prop1 = 3
myObject.myOtherObject.prop2 = "Hello"
But I get an error when I hit myObject.myOtherObject.prop1 = 3 because myOtherObject hasn't been initialized. How do I initialize an child object under myObject?
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 am busy developing an application using EF4 and MVC2. My development database has a few extra fields that is not in my production database. I have removed the fields from the Model, and published my application to my web server. But now I am getting errors that says I have some invalid column names, but I have removed it from my model. If I go to my Mapping Details, I see the fields removed from the Model are still there, but not mapped to anything.
View 2 RepliesI ahve two tables each with a primary key. There is a lookup table in between the two tables with relationships. Below is a simplified look at the table structure
Table 'Product'
Column ProductPK int (Primary Key)
Table 'County'
Column CountyID int (primary key)
Table Product_County_Lookup
Column ProductPK int (Joint Primary Key)
Column CountyID int (joint primary key)
I already have the ProductPK and CountyID. What is the correct LINQ statement to insert into Product_County_Lookup table ONLY?
i'm trying to use Entity Framework to insert into SQL SERVER 2005, using Visual studio 2008.the following codes are a Button onclick event,I want to insert into DB multiple rows at a time
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however this does not work, it seems we can only insert into DB only one row at a time
I been looking but I cant find any info on this topic Anyway I got a model that looks like this.
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I want to cascade delete a category with all its sub categories but I cant make that reference in the database, not with the option to cascade update or delete. It work fine with pagecontents and all the other I got its just this same table reference. In NHibernate I do the cascade setting hbm or with a better way using the fluent option. How do I go about this task now?
i have the following code where I want to retreive the data form a table using entity framework and put it to a list of the same type:
List<ItemDetail> iDets = new List<ItemDetail>();
iDets = (List<ItemDetail>) from l in db.ItemDetails
where l.ItemID == varItemID
select l;
when I run the page, it throws the following error:
Unable to cast object of type 'System.Data.Objects.ObjectQuery`1[LIBRIModel.ItemDetail]' to type 'System.Collections.Generic.List`1[LIBRIModel.ItemDetail]'.
why i'm having this problem? or am I missing something here if i'm not wrong it worked once, but now it throws this error
For Example, "E0001"
Everytime it will automatically incremened by 1.
"E0001" -> "E0002-> "E0003" and so on.
"E0010" -> "E0011" and so on.
"E0100" -> "E0101" and so on.
My requirement is to create an Enum based on values present in a table from DB. I am using ADO.NET Entity Framework model (.edmx file),
View 2 RepliesIs there a way to export a EF 4.0 Data Model to EF 3.5?
I looked around and found that we are not able to access EF 4.0 from a ASP.Net 3.5 project here: [URL]
Our project is the 1st to go to .Net 4.0 using Entity Framework and we (the team) were wondering if there was a way for the other projects that "might" need to access our data that are still using the .Net 3.5 framework.
I have some questions regarding the entities framework. Once you create your DataModel, if later you modify it such as removing fields adding tables it is possible for the EF to auto detect changes or you have to refresh it manually? If you have to refresh it.. how do you refresh it to reflect new changes? Also do it affect in any way the data in the database?
View 2 RepliesUsing a very run-of-the-mill database, with identity int for primary keys, a Dynamic Data Entities Project (EntityFramework) displays the primary key for view and edit. When using Linq to Sql, the primary key fields are not displayed.
I would like to hide the primary keys and use Entity Framework (VS 2008, .Net 3.5 sp1).
I'm working on a new project where I have the luxury of working from a Model to Database approach using Entity Framework 4.
The project I'm working on is taking an agile approach where different phases will be rolled out over time.
Will the Model First approach work in my case? I noticed when you "Generate Database from Model" it recreates the entire schema from scratch which will obviously wipe all the data that is in the db. I was hoping for a more "Update Database from Model" approach where the db would just be altered to reflect the changes rather than recreated
Is there a way to manually update a single edmx entity to reflect a new column in a SQL db table? If yes, what would be the proper step- by-step procedure?
I prefer not to use the "update model from db" template because this will update all the tables and wipe out all the customizations and name changes I have already made in the EF objects. This seems a bit overkill for a single column change. I went down this route once, and I prefer not to do it again. I do not see any way to actually update a single table from the DB using VS2010 "update from db".
What I have tried to do so far is manually add a new scalar property to the appropriate entity using the edmx designer, and this seems to work OK, but I cannot seem to find a way to map the new property back to the db through the mapping window. Do I have to do this directly through the XML file? Also is this sufficient to ensure the new column is correctly reflected in the edmx, or are there other steps that need to be done?
I have three table like above, table C is mapping table which has foreign key of Table A and B.How can i select and insert data in Table C using Entity Frame Work?
View 2 RepliesI am new to entity framework , it is really very good , but I want to know what is the difference between using entity framework with stored procedure or without stored procedure , which one the faster and what is the benefits for using stored procedures with entity framework.
View 1 RepliesI have an EDM, it includes the entities extension and history. My goal is to use history to keep track of all the changes made to extension entity. For example, if extension with ID 223 has its property 'Name_Display' changed - I want the history entity to record this.
I'm using ASP.NET with VB.NET. Where in my code do I put the hook to say, "update the history entity" and what should that hook look like?
I am using Entity framework to model my database (model first) however the table generator is creating tables with plural names. I have looked into the ssdltosql10.tt file. It is generating the table names from Entity set. Any way this can be changed to get the table names from "Entity Name" instead of the "Entity Set Name" so I end up with singular table names.P.S. BTW in Northwind Database the tables are pluralized however in adventure works database the tables are singular. I prefer singular.
View 1 RepliesI get an cast exception when i am trying to insert an entity in Entity Framework (using code-first). From this code :
public virtual T Insert(T entity)
{
return Context.Set<T>().Add(entity);
}
The cast exception is like "impossible to cast ...Collection'1(Entity) to type (Entity)" I can't figure out why. I am pretty sure ive done everything right. Post entity
public class Post
{
public long PostId { get; private set; }
public DateTime date { get; set; }
[Required]
public string Subject { get; set; }
public User User { get; set; }
public Category Category { get; set; }
[Required]
public string Body { get; set; }
public virtual ICollection<Tag> Tags { get; private set; }
public Post()
{
Category = new Category();
if (Tags == null)
Tags = new Collection<Tag>();
}................................
I am mapping a stored procedure to an entity by right clicking on the entity (in the .edmx) and selecting "Stored Procedure Mapping." This brings you to a Mapping Details - "Name of Entity" Window that allows you to select the insert, update, and delete stored procedures associated with the Entity. It also maps the stored procedure parameter to the Entity "Property" (Column).
I'm gettin an error "error 2042: Parameter Mapping specified is not valid." The cause of the error is fairly obvious, in the Insert stored procedure that has been selected, a 'CHAR' parameter is being mapped to an Int32 Entity Property. I altered the stored procedure parameter to match the entity, I deleted the stored procedure, readded, and reslected it as the Insert function. I also cleaned, validated, updated model from database. No matter what I do, the parameter list in the mapping details doesn't reflect the change to the stored procedure. It's stuck on a char --> int32 mapping, even though it has been changed, like it's buried deep in meta data some where.
I am trying to add a new entity and have to refernce associated data to add it. I cannot load the Referencetables. Giving "The EntityReference could not be loaded because it is not attached to an ObjectContext." How do i complete this task in Entity Framework 3.5
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I'm writing a custom .NET MembershipProvider (not the built in one) and trying to update using Entity Framework. But of course i have no access to (Try)UpdateModel. How can i update it?
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