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?
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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.
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.
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'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.
View 2 RepliesI have the following query:
Dim queryStudent = (From p In dbContext.Residents _
Where p.people_code_id = people_id _
Where p.year = year _
[code].....
I have a the following setup
m_handsets = From p In RL.App.TComEntities.tblTelephoneNumbers _
Where p.companyId = m_CompanyID _
Select p
m_handsets = DirectCast(m_handsets, ObjectQuery(Of RL.TelephoneNumbers)).Include("tblCalls")
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
c# - Are Microsoft Entity Framework and ADO.NET Entity Framework (.edmx) the same?
View 7 RepliesI want to update an entity without loading the entity from the database first. I've accomplished this but only by knowing all of the entities properties and then using the "attachto" method. My issues is i don't want my app to need to remember all of the properties. Example:
[Code]....
Entity Splitting: one class, two or more tables.Here is how it is done in C#, but I need to get it working in vb.net.One more thing: the class name and table columns do not match, so I have to be able to map that out, too.I have to get this to work this way because the place I'm working at right now is a vb.net only shop and the database schema is fubar, but they have so much (millions) of lines of code done directly against the database in both asp classic, vb.net, AND asp.net webforms that changing the schema right now is not realistically possible.
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Post>()
.Map(m =>
[code]....
I am trying to jump from ASP Classic to asp.net. I have followed tutorials to get Entity Framework and LINQ to connect to my test database, but I am having difficulties figuring out ExecuteQuery(). I believe the problem is that I need an "entity class" for my database, but I can't figure out how to do it. Here is my simple code:
Dim db as New TestModel.TestEntity
Dim results AS IEnumerable(OF ???) = db.ExecuteQuery(Of ???)("Select * from Table1")
From the microsoft example site, they use an entity class called Customers, but I don't understand what that means.
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]...
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.
Create composite and custom grid control in ASP.Net 2008 or above
I need to create composite control . My control like one "div" inside that div one Gridview control.
I'm trying to create a composite control that will look like a ComboBox with a TreeView style. I'm new to this topic and I have an urgent need to create such control. I know it's not an easy task but please I need your advice to complete what I already started to build.My approach was to combined a TextBox, button and a treeview into a UserControl and make them work together as one control to achieve the control that I'm looking for (A ComboBox with a Treeview style).
So I started by creating a new windows forms control library project and I added a text box and a button as a starting point. The text box will display the name of the selected node text of the treeview and the button will show the treeview under the text box when the user click on it.
Now I'm facing tow problems with my custom control:First when I drag the custom control to a test form the resizing of the control doesn't work properly even after I used the anchor property of the text box and button controls. If I try to resize it horizontally its working find but it's not vertically.
Second I don't know how and where should I place the treeview control and how I'm going to show it exactly under the text box when the user click on the button and hide it when the user click on one of the treeview nodes.
My company is tossing around the idea of using the Entity Framework when it comes out with .NET 4. We are currently a VB.NET shop, but have some interest in switching to C#.Is there any major arguments for or against such a move?Does EF with C# hold any advantages in performance, coding ease, etc over VB.NET?
View 10 RepliesI am a newbie. I have been able to Add new entities where there is a One-To-Many Relation. I am having a problem (don't Know how to do it) adding a new Entity when the relation is using Many-To-Many. In my EDM I have:
[Code]....
I downloaded the VB 2010 Express software, the total files that we included in the download was 15, but it only loaded up 12 of these files. The following downloads did not get loaded as follows:MS Visual Studio 2010 ADO.NET Entity Framework Tools
MS HelpViewe 1.0 x64
I tried reinstalling the downloads that did not using the VB Express 2010 setup, but they do no appear on the list of downloads, only the SP1 for MS SQL Server 2008 Express Server (x64).Do I require the downloads that did not load.
Here are the entities that i have...
Public Class Account
Public Property AccountId As integer
Public Property AccountDescription As String
Public Property Transactions As List(Of Transaction)
End Class
[Code]...
i would like to make it suc that when i do "db.Account.find(1)" for example it also loads in the list of all transactions which have the coresponding AccountId. I'm not too sure what type of relationship this is?? anyway, right now i can do
Dim acct As Account = db.Account.Find(1) acct.Transactions = from ts in db.transactions select ts where ts.AccountId = acct.accountid but i know this is not the correct way, there must be a way to map this out so that entity can just load everything in one shot right?
I am used to using datasets for my projects in terms of data access. I now set myself an easy app to work on in order to learn the entity data framework and how to retrieve & manipulate data.Can anyone guide me through on where to start, what are the advantages of this model, In what scenarios should I choose to use entity framework and what are the things (basis) I should now before starting.My datasets are working fine too. Are there any reasons for me not to stick with that way of accessing data? Or is this something to consider depending on the users of the website (for speed purposes etc.)
View 3 RepliesI'm trying to learn EF in visual basic. I'm struggling with finding any easy to understand simple tutorial of how to do inner joins.
This is the SQL that i'm trying to replicate in EF:
SELECT Quote.LockedDateTime, IncommingQuoteStatus.StatusDesc, Users.FirstName
+ ' ' + Users.LastName AS UserName
FROM Quote
[Code].....
I have some basic expirience in Visual Basic and programming Windows Forms programs. I know now that forms programs are no longer updated by Microsoft and that WPF is the way to go. No to mention the slicker interface you can create. I've also noticed that passing SQL strings to a database is no longer the standard either. It's either Entity Framwork or Linq.
So I am going for a fresh approach. I need to develop a program that will access a sql database and be accessed by about 10 concurrent users within the office. What's the best approach in general? Linq or Entity Framework? Also, could you recommend a book or two for someone who is new to WPF and Entity Framework? I do have some programming expirience, just none with WPF or the new ways of ADO.net 4.
How to create composite grid. ie , i need all the features of gridview in the Framework 3.5 and above,but also need to include some other functionality to that grid.please suggest me what to do . if possible please share sample code.
View 2 RepliesI'm currently testing the entity framework 4 for a simple app I wish to build.
how do you save and cancel changes on a record basis? Using the save changes method on the context persists all the changes to the database.
I'm trying to use the Entity Framework to create a complex query and get stuck in the joins. After browsing some of the documentations, I cannot seem to find the correct solution, so maybe someone here can help.
I have a data structure where a family has several family members, each of which can have more than one entry in the income table (on different registration dates) and can have more than one entry in the healthconditions table.
[Code]...
I need to make a if-else statement in the query meaning I only want to add the OpenAmount to ExpectedAmount if the type = Cash, the problem is that it only gives me the cash row not the other row.
[Code]...
I'm working on a project that was built using ADO.NET (raw sql) and Active Record pattern. I am slowly moving it away from ADO.NET to Entity Framework Code First 4.3.Here is an example of the pattern. The interface is a static Load and an instance Save (and Delete -- not shown).
Public Class Part
Public Property Id as Integer
Public Shared Function Load(_id As Integer) As Part
[code].....
