Entity Data Model And Insert With Identity Property
May 6, 2010
in a new project I thought I would try to integrate the new Entity Model Framework, but am having some issues/problems and would like to know if there is a solution or workaround that will let me insert a record into a table that has an identity property.At first I thougth it might simply recofnize the storedprocs that I have for insert/update/delte actions, and was a bit discapointed when generating the model ignored all my stored procs. So I thought wll heck maybe it just generates a nice insert method for me. Lets see.So I referenced my model and found that for the table (entity) there was an insert action (method) that had been generated, however what i found is that it explicitly added the primarly key field - which was based on an identity property and will not accept an explicit insert value.So I guess 2 questions
1. How do we work with identity properties
2. How can we take advantage of the performance and securtiy advantages that stored procs offer with SQL server?
I have two properties ("FIRST_NAME" and "LAST_NAME") I need to access as a single property (e.g. "FULL_NAME"). Is there a way for me to add a property to my entity model that contains the combine value of FIRST_NAME and LAST_NAME?
I'm pretty new to the EDM, so bear with me. I have a windows form that has a DataGridView on it that's bound from the EDM I created. I figured out how to update my changes fine, but it's when the user creates a new row that I'm having a problem.I tried numerous ways and many google searches, but came up with nothing so far.
[Code]...
Error (occurs when calling _Context.SaveChanges()): Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries.
I am working on a silverlight project in which i am using the entity data model. I have a consol application in the same solution through which i am creating the database table at runtime. Now when i moves to silverlight page i need to Communicate (load data from newly created tables).But problem is that without updating the model how i will able to communicate with that table at runtime using entity framework model.
I have a GridView that is tied to an EntityDataSource. Most columns are normal bound columns, but two are itemtemplates. When I attempt a delete on one of the rows I receive the following message:
"A property named 'Building1.building_name' was not found on the entity during an insert, update, or delete operation. Check to ensure that properties specified as binding expressions are available to the data source."
I'm not sure how it is possible that this isn't available, since it displays the element just fine when I'm just viewing - it just throws the error when I attempt deleting a row?
I have a misunderstanding somewhere with the Entity Framework. This code is from my unit testing:
Public Sub UpdateRosterLinkTest() Dim target As PlayerAdmin = New PlayerAdmin() target.PlayerAdminManager = playerAdminTestManager target.Team = playerAdminTestManager.GetAirForceMensBB()
[code]....
When I run this code, I can see the changes saved to the SQL Server this pulls from (RosterLink = Roster Link, like I set in the unit test).However, my unit test is failing, because team.RosterLink is still Nothing. The function GetAirForceMensBB() returns the Team with TeamId = 12434:
Function GetAirForceMensBB() As DAL.Team Return (From team In Container.Teams Where team.TeamId = 12434).SingleOrDefault End Function
I'm sure I'm using the entity framework incorrectly and it probably has something to do with the fact that I am calling the PlayerAdminTestManager in different places, but I don't understand why. Although, I set the PlayerAdminManager to be the PlayerAdminTestManager. PlayerAdminTestManager extends PlayerAdminManager, fyi.Why is team.RosterLink not showing the update from UpdateRosterLink?
EDIT:Container is my ObjectContext. This is how I access the information stored in the database.Container.Teams represents my Teams table.
I am using MS Visual Basic Express 2010 and trying to generate "ADO.Net Entity Framework" entities from an existing local SQL Server Express database.
Using the "Entity Data Model Wizard" I am asked to configure a connection. Here I prompted to choose a "Data source" and given two options 'Microsoft SQL Server Compact 3.5' and 'Microsoft SQL Server Database File'. I select the second option.
I'm then prompted for connection properties, I have to enter the "Database file name (new or existing)". Here I browse to the SQL server database file of interest (found using Management Studio Express) namely[code]...
Whilst going through the "ADO.Net Entity Data Model" wizard, I select 3 tables from within a Database to add to my edmx file, and when the file is generated only one of the three tables is there. There was no error or warning to explain why the other tables haven't been added. If I try and add one of the failing tables on its own, again, nothing happens.I am using VS 2010, SQL Server 2008.
Any ideas as to why these database tables are failing to create? I realise there isn't much detail to this question, but there isn't much detail to the situation - It really is a database with 3 tables, of which 2 are failing to create through the wizard with no error.
We need to store a list of data we pull from another table that relates to one of our models. (We are too deep into build to add this relationship to our DB where it should be.) When we attempt to load this list in a property of the model that needs it.We load this list into a dropdown in a view. The error occurs trying to load this list into the model in the controller. The true caveat is that we have a unique dropdown list for each record in our table in the view.
Our Class: Public class OurModel public property ID As Integer[code]....
Error: LINQ to Entities does not recognize the method 'DB.ModelTable get_Item(Int32)' method, and this method cannot be translated into a store expression.
UPDATE: The issue appears to be that LINQ is trying to do something with a the DBContext of a query I do previously in this controller. The error is referencing DB.Employee not DB.Position which is what I am querying.
where m_handsets is defined as Private m_handsets As IQueryable(Of RL.tblTelephoneNumbers)
which works as expected however what I want to do know is query the Navigation property (tblCalls) so I can do something like the following From p In m_handsets.tblCalls Where m_handsets.tblCalls.price > 100
I think the complexity comes here because in this instance I could have 5 tblTelephoneNumbers in m_handsets and then x amount of calls for that particular telephone number. I am interested in the tblCalls for each but I would like to filter them all for each tblTelehoneNumber.
Entity Diagram which (hopefully) should illustrate further So I currently know all the handsets that are associated with the company I am interested in. I can also see the calls loaded as a navigation property in debug mode, but I want to say is take this filter (in this example price>100 and apply it to all handsets->calls
In entity framework we can use 3 approaches model first , code first , database first but each one of them needs manual hand touch(means creating database or create model or write the POCO class codes or entity class codes) before proceeding to the next step ( using EF in context ).What if I want to create database and tables and table relationships programatically and still want to have to features of EntityFramework 4.3.
To be more specific ,from this example http://support.microsoft.com/kb/307283 we can create database , tables and everything using SQL command but we can't have the advantages of entity framework. So if we want to have that what should we do? To give the ability to create dynamic table fields those steps will not be sufficient. In all 3 steps database , table and table columns are fixed. There is no way that a user can create new tables or columns dynamically. http:[url].... in this post , it shows how to create manual db, tables and etc using SQL but it is based on ADO.NET but I want Entity Manager to do that.
There are only about 30 different "Type_And_Model"-types.How can I insert into a new DataTable (dt2) only distinct "Type_And_ Model" types with the sum of their specific values and total appearance number?
CREATE TABLE [dbo].[Orders]( [OrderId] [bigint] IDENTITY(1,1) NOT NULL, [GoodId] [int] NOT NULL, [CustomerId] [bigint] NOT NULL,
[code]....
as you see the column of OrederId is IDENTITY i try to insert record in this table and when this record holding particular data i want to make a copy of it in Debts table?
The application contains a GridView which displays the records of a user table from my created datable. The database is an Sql server database.
The code below inserts data into one table and through the built in function @@Identity to insert the most recently added record id (tt_id) from the trainingTbl table and inserting that record id into the userAssessmentTbl. Adding the identity to the second userAssessmentTbl table works fine.
[code...]
The issue I'm having seems to be centered on how I insert a uniqueidenifier from a GridView into a userAssessmentTbl database!
And how, I guess using a loop I can insert the UserId records from that Gridview (GridView1) into the userAssessmentTbl table along with the looped id from the @@Identity.
This part of the insert parameter seems to be incorrect:
[code...]
And the error I'm met with is: 'Conversion failed when converting from a character string to uniqueidentifier.'
I've also tried it like this:
[code...]
And im met with the error: 'Operand type clash: int is incompatible with uniqueidentifier'
The qusetion has slightly changed to how do I Insert a String into SQL DB Where DataType Is Uniqueidentifier?
If I a many-to-many relationship between Users and Roles and I have an instance of a User entity and several Role Ids can I insert a relationship between the two types of entities without having any other Role data and without doing a select on the Roles first? Update:
I might not have been clear enough. I don't have an instance of a Role, only the role id. Is it possible to create the relationship between User and Role without filling a Role object from the database first?
I have a simple Entity Framework. For simplicity's sake I will transform the entity names to Northwind Like.I have a IEnumerable Of Customer and Item Objects
I have been reading some articles on unit testing but I still have some questions.
- What should be tested if we want to test if an entity can be saved or not? - Should we test each and every property of the entity? - If I have a solution consisting or 3 projects, will the unit test go become the 4th project?
I'm struggling a bit with Entity Framework 4.x. Let's say I have a model called Product. It was generated from a database table. There is a field in this entity called CreatedDate. The MySQL database has a default value for the current timestamp. I don't want Entity Framework to set this field when inserting or update the table. Problem is, I can't seem to figure out how to tell EF to exclude this field from being sent back to the database, but still retain it as a field to be viewable in the application.
VB .NET 4 WinForms application. I have a (DevExpress) grid bound to an IEnumerable(Of MyClass). Whenever a new row is added, the ID defaults to zero (0). On trying to SaveChanges, EntityFramework doesn't realise that being an identity field means it should ignore any contents on insert and just insert the other values. I can't specify null / Nothing because it just keeps the ID as zero. I can add and save instances of MyClass manually, but I'm trying to get it to work where the grid handles adding/initialising/etc new entries. As far as I can tell, the problem is not with the grid but with Entity Framework and the generated SQL and entity classes. {"Cannot insert explicit value for identity column in table 'MyClasses' when IDENTITY_INSERT is set to OFF."}
Given a string of categories, I need to split the string and insert each separate item as a new record using EF.The following does not work since string cannot be converted to Tag:
Dim s = "Books, Novels, Magazines" s.Split(", ").ToList.ForEach(Function(x) _rdsqlconn.Tags.Add(x))
How can i split the string and insert each as a new tag record?
I'm new to EF. I have some code that successfully inserts a record in a table. However, it uses the autogenerated "addto." method which I understand is depreciated. I've seen references to using the "add" method but am having trouble.[code]What is the "correct" way to insert this record (vb please)?
I am trying to learn how to program using LINQ to SQL so I downloaded a Tutorial Paper on datacontext and other subjects but cannot get very many of the examples to build with out errors as written in the Tutorial. The code that I am trying to run is as follows.[code]...
Even though I had to make some additions to solve undeclared variables it run up to the db.SubmitChanges() statement which give me an error message declaring the following "Cannot insert Explicit value for Identity column in table orders when IDENTITY_INSERT is set to off. I used SQL Server Management studio to attach the database and ran a query to turn the IDENTITY_INSERT to on but when I detach and try to run my code against the database I keep Getting the same error. I can look at the ord variable and see that the OrdersID Var is set to nothing. I tried to give it a number 1 higher then what was in the database but it still didnt work. I have looked all over the internet and found much information using scripts and querys in SQL management studio to turn IDENTITY_INSERT on and off but none to do it from visual basic SQL to LINQ code.
in the sense that MVC does not complain about my protected inner abstract Metadata class, and the model validation still works:
Partial Domain Object, generated by a tool: Partial Public Class SampleDomainObject Private _id As Integer
[code]....
I did this because I didn't want to have to implement actual properties with backing fields, getters, and setters in VB.NET for the Metadata class to keep the maintenance to a minimum (I'm on .NET 3.5, no auto-properties for me).What I'm worried about is that having a protected abstract inner class could be confusing to others using this domain object outside of MVC (my domain objects are part of a shared data access framework).
I use Visual Studio 2010 and SQL Server 2008 R2. I have created an Entity Model in a class library which I have referenced in a VB Winforms project. I created a data source in the project based on the entity model in the dll. However, all columns in the data source are listed in alphabetical order instead of the native order from the SQL Server database. I cannot locate the cause of this as much as I try.
This might not seem a huge problem, but it is costing me valuable time in rearranging controls dragged to forms and reindexing their tabstop indexes.
I am trying to build a survey engine from an existing database design which is like this.
[Code]...
The line Order By Key.RecordOrder throws a null reference exception and I can understand why. Can someone advise on how to resolve this by just modifying this one query? I am fairly new to LINQ and the necessity to write this project
