when i create my entity data model i have a situation in the DB like this :
TableFirst : [Id,IdTableSecond,IdTableSecondAgain];TableSecond[Id] Created data model is: TableFirst.TableSecond and TableFirst.TableSecond1 Question is: Every time when i create my entity TableFirst.TableSecond will have same relation in behind (IdTableSecond) and TableFirst.TableSecond1 (IdTableSecondAgain) or they may change?
MVCThe generated ADO.NET Entity Data Model loses ordinal positions of columns and reorders Entity Set column names alphabetically. This causes the columns in a new MVC VIEW to appear alphabetically and needs to be reordered by hand. I am using MySQL Database.
How can I retain the ordinal positions of columns?
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...?
I can't to understand clearly how to create strong and quickly application using EF. For example, I have class ForumPost (table ForumPost) for select one of record I write method like:
public ForumPost ForumPost(int ForumPostID) { return (from i in _dataContext.ForumPostSet where i.ForumPostID == ForumPostID select i).First(); }
all works. But on page (I use ASP.NET MVC) I should display info from another linked tables, ForumName (each post have ForumID) etc. So, I modify this method to:
public ForumPost ForumPost(int ForumPostID) { return (from i in _dataContext.ForumPostSet .Include("ChildPosts").Include("ParentPost").Include("Users").Include("Forums").Include("Tags").Include("ForumPostPolls") where i.ForumPostID == ForumPostID select i).First(); }
ok, all works. Then I want to make some actions in model with ForumPost, i.e.
public void RootPost(int PostID, ref Models.ForumPost Root) { ForumPost post = ForumPost(PostID); if (post.RootPost != null) { Root = ForumPost(post.RootPost.ForumPostID); } else Root = post; }
it works too. But problem is in speed. I not need in RootPost all those includes. So, I should to create one more method like:
private ForumPost ForumPostIncludes1(int ForumPostID) { return (from i in _dataContext.ForumPostSet .Include("ChildPosts") where i.ForumPostID == ForumPostID select i).First(); }
then ForumPostIncludes2, ForumPostIncludes3 etc... second way - redesign RootPost with LINQ expr, not with call another method. But in this way difficulties to change DB. third way? How to do it correctly?
getting data from multiple Entities models into an MVC controller. Most of the examples I have seen for using EF in an MVC2 app only use a single entitiy.
I have just started using MVC2 in C# using the Entity Framework models (CIOps.model) created from an SQL database. I can create the controller and views using single tables of the model in MVC2, but I just cannot get my head around how to get data from multiple entity tables into the controller (similar to joins in T-SQL). I have included an example below of the controller code that works with a single entity table, tbl_tours (tbl_tour in DB).
Could someone please illustrate how this code would be changed to include additional columns from FK tables in addition to tbl_tours columns. E.g. the clients name from the tbl_clients, the coordinators name from the tbl_employees, and costs from tbl_costs entities? Is it possible to do this directly using the EF model entities/classes that are already created and not use LINQ, POCO, Repositories, etc.? The FK relationships are already in the EF models. I have included the whole controller code, but I just need a few examples of how to join the multiple entities, not rewrite every CRUD function function in the controller. I think this will get me over the hump in using EF in an MVC2 App. Also ignore the fact I am using the home controller, this will change in the application.
Am trying to get a working enity model with foreign keys working but have run into a problem. I have imported 3 tables with content and some data.Lets call these tables geo_countries, geo_counties, geo_municipalities and the FK are:1. geo_county have a column country_id wich corresponds to country_id in geo_country 2. geo_municipality have a column county_id wich correspond to the county_id in geo_county.The problem i have is when i try to get correspondig child items with the following code i run into trouble:
[Code]....
The problem above is that 'test' generates results but not 'test2', wich never return anything. Am i not supposed to be able to do it like i do in 'test2'? I earlier tried to add a child object by replacing ToList() with Add() and that worked. But i cant seem to get anything out of it.
I am getting error while accessing entity model from web serviceSystem.NotSupportedException: SQL Server Compact is not intended for ASP.NET development. at System.Data.SqlServerCe.SqlCeRestriction.CheckExplicitWebHosting() at System.Data.SqlServerCe.SqlCeConnection..ctor() at System.Data.SqlServerCe.SqlCeProviderFactory.CreateConnection() at System.Data.EntityClient.EntityConnection.GetStoreConnection(DbProviderFactory factory) at System.Data.EntityClient.EntityConnection.ChangeConnectionString(String newConnectionString) at System.Data.EntityClient.EntityConnection..ctor(String connectionString) at System.Data.Objects.ObjectContext.CreateEntityConnection(String connectionString) at System.Data.Objects.ObjectContext..ctor(String connectionString, String defaultContainerName) at DataModel.LabTestDBEntities..ctor() in d:projects4.0 vs2010labtestlabtestsolutiondatamodeldbmodel.designer.cs:line 26 at DataService.Service1..ctor() in D:Projects4.0 VS2010LabTestLabTestSolutionDataServiceService1.asmx.cs:line 23
Really new to C# & Web developing - but have used the DAL & BLL model from a number of the turorials. Have a situation that I not sure the best way to accomplish. I have an application dealing with courses, books, etc. utilizing an Access Database. All was going well in creating an on-line catalog using Formview and tables to display the db values stored in the Course Table (Course ID the key). User is able to use dropdown list to locate the course - dropdown list showed the Course Nbr & Name, but used the Course ID to get the detail. This issue appeared when they introduced a Prerequisite field in the Course Table. This contains the Course ID of the prerequisite course, but they want to display the Course Nbr and Name in the table field. So today it show 18 (Course ID) and they want B101 Intro to Biology. Hope I have provided enough information of what the code looks like below
Here is also the OBJECT DATA SOURCE <asp:ObjectDataSource ID="ObjectDataSource1" runat="server" OldValuesParameterFormatString="original_{0}" SelectMethod="GetCourseByCourseID" TypeName="CoursesBLL"> <SelectParameters> <asp:ControlParameter ControlID="DDLCourse" Name="CourseID" PropertyName="SelectedValue" Type="String" /> </SelectParameters> </asp:ObjectDataSource>
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()
I am a newbie in mvc3 and i'm wondering how to use attribute like [Display(Name="")] for model that comes from an entity data model that I provide im my "Model" folder in my mvc3 project.
I didn't provide a .cs class for each of my database tables .
other words, I want the controller class render a edit form for me like :
I made a few changes to the DB in SQL server management studio then right clicked on the .edmx doc to get it to update. That seemed to work fine but when i compiled the app everything that referenced the EF seems to be broken.The Error list now contains the below error for all classes that used it.
The type or namespace name '' could not be found (are you missing a using directive or an assembly reference?)
I program in ASP.NET for a while now. My applications uses always the DataSet. Some told me that Entity Data Model is the DataSet for LINQ. Now I want to try to working with it I have some questions but can't find the answers. I hope someone can. When I build an application I use the 3-tier structure. So Presentation-layer, Business-layer and the Data-layer. Normally I had some classes in the Data layer with specific methods to interact with the DataSet. When I read the table or something I create an object for the business layer.
With the Entity Data Model it seems a little bit confusing. If I read a table (for example Company) the edmx has created an class already. So is the edmx a replacement for the Data-layer and also for the Business layer? Is the edmx also a good use for multi-user application or is a connected application better?
For VS 2010, I am trying to add new item of existing mdf file. By : Add new item -> Data -> ADO.NET Entity Data Model -> Generate from database.
When I reach the step of "Choose Your Data Connection", under the : "Which data connection should your application use to connect to database?" The combo-box is empty. How can I make that combo-box not be empty (some configurations?)
Is 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 followed this tutorial [URL] to get a google map displayed but now I want do the next step and read the long/lat and text out of my ADO.NET Entity Data Model and put it on the map (preferably the text should appear when clicking on the red spot in a white text box - as you know it from google). Has someone done this already and could let me know how I get the points on the google map? THis is how the function in my controller looks right now:
Function Map() As ActionResult ViewData.Model = (From m In _db.ahn_mappoints Select m.LONG, m.LAT, BLOG = m.Text.Substring(0, 81) & "...").Take(2).ToList() Return View() End Function
We're upgrading our system core asp to asp.net mvc, but there is a problem with refreshing the Database Model, our system is a UDP listener Windows Service, and Instering data to our database, our web system reading the database and process it then render. Here is the problem, When i enter some data using DatabaseModel, there is no problem, but when Windows service insert records to database, i can see the record at the web, is there a way to refresh entity data model/
How can I share the auto-generated entity data model (generated object classes) amongst all layers of my C# web app whilst only granting query access in the data layer? This uses the typical 3 layer approach: data, business, presentation.
My data layer returns an IEnumerable<T> to my business layer, but I cannot return type T to the presentation layer because I do not want the presentation layer to know of the existence of the data layer - which is where the entity framework auto-generated my classes.
It was recommended to have a seperate layer with just the data model, but I'm unsure how to seperate the data model from the query functionality the entity framework provides.
