C# - Difference Between .edmx File And Creating An Entities.cs File?
Mar 15, 2011
I have looked at two of Microsoft's tutorials for MVC. In one tutorial they are creating a .edmx file to handle the Entity Framework in order to execute Linq queries. In another tutorial they made a class called "MusicStoreEntities.cs" here is the code:
using System.Data.Entity;
namespace MvcMusicStore.Models
{
public class MusicStoreEntities : DbContext
{
public DbSet<Album> Albums { get; set; }
public DbSet<Genre> Genres { get; set; }
public DbSet<Artist> Artists { get; set; }
public DbSet<Cart> Carts { get; set; }
public DbSet<Order> Orders { get; set; }
public DbSet<OrderDetail> OrderDetails { get; set; }
}
}
And the tutorial creates an instance of this class and starts doing Linq queries as well. What are the differences between these 2 methods? and how can I make DbSet objects in a .edmx file?
My Question is can we extend one context to another in Entity Framework 4. Following is the problem background.
I am using EF4 for developing a Web-Application. My Web Application has 3 projects.
One project is for storing candidate CV information.
Another project is for storing customer information.
Final project is called CORE. this CORE contains a edmx file that should be extended by CV and CRM.
As an example email address table can be shared by both customer (CRM) and CV. To share one table with another, we should be able to extend one context (CV context) with other context (customer context). Could some one having experience using Entity Framework share your experience with me to find whether this is possible.
We have 3 edmx files in three class libraries:
Person class library(Core) with core.edmx-Basic details related to a person(name, email) CV Class library with CV.edmx wich have CV related data(Experiance,skills) Customer Relationship management system(CRM) which have customer data(sales data...)
Then we want to use core class library edmx file(Core.edmx) with cv.edmx (basically cv tables should be able to use tables from core tables) . Same way we want to use the core.edmx with CRM.edmx for the 3 rd project
When I try to add a new stored procedure to an EDMX file, I try to get the column information for a complex type, I get the following error and can not register the stored procedure:
An exception of type Microsoft.SqlServer.Management.sdk.sfc.EnumeratorException occured while attempting to get column information. The Exception is:
ExecuteScalar requires an open and available connection. The connection's current state is closed. The inner exception caught was of type System.InvalidOperationException withthis message: Execute scalr required an open and ready connection.
I cann ot add the new stored procedure but everything compiles fine.
We are using entity framework and we have two projects with two different edmx files. We need to keep both tables in same database and we want to extend funtionalities of one project by the other one. Is there a way to extend edmx files or is there a better solution for this?
we have 3 edmx files in three class libraries.
1.person class library(Core) with core.edmx-Basic details related to a person(name,email ...)
2.CV Claas library with CV.edmx wich have CV related data(Experiance,skills... )
3.Customer Relationship management system(CRM) which have customer data(sales data...)
Then we want to use core class library edmx file(Core.edmx) with cv.edmx (basically cv tables should be able to use tables from core tables) . Same way we want to use the core.edmx with CRM.edmx for the 3 rd project
when i delete Table (Entity Set) from edmx file ... it deleted from design but when i'm trying to add that table again to edmx file it doesn't appear in added table and when i open edmx file by xml i found table and its relation still in edmx xml so how can i delete entity set (table) completely from db note : i don't want that solution ...i want another easy solution [URL]
I'm working on the big project who has edmx file with lots of table. I want to update a table from DB. But when I update the edmx file, it also refresh the other tables from DB. How do I update single table?
I have a web project with a data model defined in an edmx file. The connection string starts like this:
metadata=res://*/;
This has worked fine for a while. But somebody else working on the project created a dll that also uses the entity framework and added it to the bin folder. Now when I try to create my connection there is an error loading the metadata.
Aside from totally changing the way one or both of us is doing things, I wonder if the problem can be fixed if my connection string can be changed to only look for the metadata defined in my edmx file. The problem is, for the life of me I can't find the right syntax to do this. The metadata is embedded in the output assembly, so there are no physical metadata files to point to. How exactly should I specify the metadata location in the connection string?
I would like to make some changes to my EF4 edmx file without modifying the file itself, mainly so I don't loose all my changes if I regenerate the model from the database. I'm familiar with XSL and have seen references made to using it in conjunction with the edmx file. This sounds like a great solution, however I can't seem to find any documentation on how to actually set this up. Do you reference the style sheet from the edmx file or do you configure it to look at the template and then load the edmx file in somehow?
Clarification:
Specifically what I'm trying to do is modify the model so that several of the views act as tables with relations within the model, see here: http://blogs.msdn.com/b/alexj/archive/2009/09/01/tip-34-how-to-work-with-updatable-views.aspx
The issue I'll have in using that method is if I need to update the database and regenerate the model I'll have to go back and make all of those changes again, I was hoping there was a way to use xslt to make those changes to the views so they would not be removed when the model is regenerated.
I have a stroed procedure which is mapped in myEDMX file under EntityContainer >>Function Imports. When I add or remove a column from the stored procedure, I am not able to remove the old columns from the model. I right click on the stored procedure in Model browser and got to Edit Function Import. The return type is complex.
I select "get column information" and get the updated return fields but can not update the collection. It will work if I click on "Create New Complex Type" but it will generate a new name for the collection and the old collection is still in the mode. I even tried deleting and adding the stored procedures and can not get it to work. I can only edit the edmx.cs and the XML to remove it but there is got to be a better way.
I need to add a table to a .edmx file. Earlier I had added that table, say, Table A to the edmx file. Since keys were not set, I had to delete it. Then in order to bring back the altered Table A to the file, I right clicked the file and clicked the option 'Update Model from Database'. But I couldn't find the table I deleted from the edmx file. It is there in the database. how can I bring the table back to the edmx file.
I am building an application using Asp.Net 4.0 and Entity framework 4.
I have already created the model class (edmx) file using the Database-First method of the Entity framework.
Now I am almost nearning the end of the application. I have realised I need to add one more table to my database.
How do I add the newly created table to the model class (edmx) file.
If I again regenerate the model class, similar to what I did the first time i.e using the Database-First approach, will my current application be affected.
Will the already in use data like tables, relationships and views be affected in anyway.
Do I have to follow this approach everytime I need to add a new table to the entity model class.
I have created an excel sheet from datatable using function. I want to read the excel sheet programatically using the below connectionstring. This string works fine for all other excel sheets but not for the one i created using the function. I guess it is because of excel version problem.
OleDbConnection conn= new OleDbConnection("Data Source='" + path +"';provider=Microsoft.Jet.OLEDB.4.0;Extended Properties=Excel 8.0;";);
which i can create an excel sheet such that it is readable again using above query. I cannot use Microsoft InterOp library as it is not supported by my host. I have even changed different encoding formats. Still it doesnt work
I have POCO's in a separate project and now I need Self Tracking Entities. Does anyone know if I need to generate new POCO's that are self tracking and they will replace my current POCO's? Or, do I setup self tracking entities in addition to my current POCO's?
I recently started explore MVC and just tried some samples around, i.e. MvcMusicStore.
As the sample DB in MvcMusicStore is quite small, I am wondering how should I design the edmx/entity for a bigger database, let say for an enterprise application, which has more than 20 tables as in AdventureWorks?
Thus, the question is should I include all in one edmx/entity or I should include multiple edmx/entities when I designing the model?
What is the fastest and safest way to download a tool and see the difference between the 2 web.config files? Does windows xp has a built in tool to do a visual Diff on 2 files?I am running Windows XP professional SP3 on my computer.Would downloading Windows XP Service Pack 2 Support Tools cause an issue?
Given the following code which is extremely generic, I was hoping someone could tell me a bit about what is going on behind the scenes...
[HttpPost] public ActionResult Load(Guid regionID, HttpPostedFileBase file) { if (file.ContentLength == 0) RedirectToAction("blablabla.....");
var fileBytes = new byte[file.ContentLength]; file.InputStream.Read(fileBytes, 0, file.ContentLength); }
Specifically, is the file completely uploaded to the server before my action method is invoked? Or is it the file.InputStream.Read() method call that causes or rather waits for the entire file to upload. Can I do partial reads on the stream and gain access to the "chunks" of the file as it is uploaded? (If the entire fire is uploaded before my method is invoked then it is all a moot point.) Is there any difference between IIS6 or II7 here?
On my master page (for all pages in my site) I have a ToolkitScriptManager.
On my content page, there are a series of hyperlinks and divs for collapsible functionality.
The code to show/hide the panels work like the following:
[code]....
If I include a ScriptReference to the jQuery 1.4.2 file in the toolkitscriptmanager, the javascript code is executed incorrectly on the page (only the text for the hyperlink is changed, the div is not actually shown.) However, if I don't include the jQuery file in the ToolkitScriptManager and instead include it in the content page, it works correctly.
We have a .aspx file which has about 400 lines of javascript code. Is it a good idea to have such huge code in its own file? What is the performance difference in having huge javascript code in aspx as against the .js file?
As the title implies how can I create a new log file each day in C#? Now the program may not necessarily run all day and night but only get invoked during business hours. So I need to do two things.
How can I create a new log file each day? The log file will be have the name in a format like MMDDYYYY.txt
How can I create it just after midnight in case it is running into all hours of the night?
I have the following code that creates a new Excel file in my C# code behind. When I attempt to save the file I would like the user to select the location of the save.
In Method #1, I can save the file my using the workbook SaveCopyAs without prompting the user for a location. This saves one file to the C:Temp directory.
Method #2 will save the file in my UsersDocuments folder, then prompt the user to select the location and save a second copy. How can I eliminate the first copy from saving in the UsersDocuments folder?
I am creating a PDF template file and I will want to use that to create other files. I have been looking around and found the following code:
[Code]....
The problem is that pdfreader, pdfstamper, acroreader are underlined and it says it is not declared so I couldn't test it, I wasn't sure what I had to import in order for it to work. In addition, if you have any other way that is easier to use let me know.