Update / Insert At Same Time Using Entity Framework?
Aug 29, 2011How to update the existing Customer object, Insert new Computer object and Add new WorkOrder using entity framework? [code]
View 2 RepliesHow to update the existing Customer object, Insert new Computer object and Add new WorkOrder using entity framework? [code]
View 2 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]....
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
View 1 RepliesVB .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."}
View 1 RepliesI'm trying to update a specific record based off of a users selection. Regarding Entity Framework syntax, I'm not very familiar. Is it possible to achieve this SQL statement in Entity FrameWork?
View 3 RepliesI would like to update a row like this:
update [approvers] set approvalstatus = True Where approvalstatus = False and bookingID = @bookingid and approveremail = @email
Using the entity framework.
I have my query which should deliver the item like so:
Dim db As New Model.Entities
Dim approvers = From a In db.approvers Where a.ApprovalStatus = False And a.BookingID = BookingID And a.ApproverEmail = UserName Select a.ApprovalStatus
How do I next target this record for update, so that I can set a.approvalStatus = True then commit these changes to the db?
I'm trying to update one value of a compound primary key from within the entity framework and I'm getting this error: "The property 'CustomerID' is part of the object's key information and cannot be modified. "[code]...
View 4 RepliesGiven 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)?
View 2 RepliesI have 2 tables in my DB: "Competitions" and "CompetitionAnswers". Each competition will always have 3 answers. I want to be able to edit the Competition and CompetitionAnswers for the same view. I have managed to get the view to work by using editor templates So this is my editor template:
[Code]...
I'm using EF version 4.1, and would like to have the data from the database in realtime, i.e. if you open the application it detects if there is new data in the database, and update the above it! is It possible to do this? I am using EF 4.1 code first time
View 1 Repliesc# - Are Microsoft Entity Framework and ADO.NET Entity Framework (.edmx) the same?
View 7 RepliesI 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?
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'm not so good in databases and SQL. At the moment, I have a interface of a simple payroll system as well as a database design. I got 4 tables consist of Employee, Payroll, Deduction and Salary as you can see in the picture link below. Btw, I'm using VB 2008 express edition and mysql 2008.
Interface Design: [URL]
Database Design: [URL]
My question:
How can I link them properly? did I link them properly? How can I save the data into 3 different table from the interface u can see.
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.
I'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].....
I have the following code:
Private Sub btnReserve_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnReserve.Click
Using dbContext As pbu_housingEntities = New pbu_housingEntities
[Code].....
executes it always get 0, because the row has not yet been created in the database. I can just move this last bit of code out into its own Context, but is there a better way to do this?
I am trying to make an MVC index view with bulk editing functionality, but can't seem to get it working. I have replaced the Html.DisplayFor with HTML.editorfor items, and put the whole table in a form which submits back to my index function. I have tried various ideas, but currently my function is
[Code]...
I am just starting out with ADO.net Entity Framework I have mapped two tables together and receive the following error:
Error 1 Error 11010: Association End 'OperatorAccess' is not mapped. E:Visual StudioprojectsBrandi IIBrandi IIHospitals.edmx 390 11 Brandi II