Generally what is m.v.c model in software application development and entity framework in asp.net and are these diffrent form 3 layer d architecture(UI layer, Business access layer, Data access layer)
View 2 RepliesI 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?
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.
There are some tutorials explaining how to create a Model based on Linq to Sql or The Ms Entity Framework. Can I use my custom code for a model? If we have the controller with the code :
[Code]....
This returns a List<Movie> to the view that knows what to do with it. Is it possible that I create a method called MovieSet that returns a List<Movie> using a sql qry or a stored procedure call without the creation of an Object for this purpose ? Or do I need a Movie object? Lets say that I just to do my query, loading data into a dataTable and load that data to a list of movie objects. Because the code created by the Entity Framerwork is too big for a quick reading.
I want to use entity framework model for visual studio 2010. I am using oracle database. i was wondering if it is possible to use entity framework for oracle. If it is not possible then I will just use simple ADO.net and call stord proc and packages. I already downloaded oracle data provider for entity frameowrk from codeplex web site. I could not see oracle database option when connecting to oracle databse in LINQ to sql. can someone give me any example that connects to a sample oracle database and use LINQ to oracle
View 1 Repliesi am calling stored procedure through entity model like result=ctx.spname(parmas), i am expecting 0 or 1 as a result after the execution of sp, but its returning unknown values like 178 for number records.
View 2 RepliesI am making a web project now. And i meet some problems working with Entity Framework. My program needs to have dynamic model. I try to explain. So i have classes and database is created from them. At the beginning of work program checks in folder Modules for assemblies and looks for classses that needs to be created as tables in database(this classes have to become a part of ef model). And i need at runtime create database.If some new classes was added so add this tables to database, but not recreate it(as it is made by default). If i delete classes the tables are not deleted.
View 2 RepliesCan I generate entity framework model by clicking button in browser in client-side and save it back to web server PC?
View 2 RepliesI want to use entity framework model for visual studio 2010. I am using oracle database. i was wondering
if it is possible to use entity framework for oracle. If it is not possible then I will just use simple ADO.net and call stord proc and packages.I already downloaded oracle data provider for entity frameowrk from codeplex web site.can someone give me any example that connects to a sample oracle database and use LINQ to oracle
I am using C# with Entity Framework Model. I want to fill a textbox (tbPrepProbComment.Text ) with a string (S0PrepProbSolveComment) from a table (EightDProject). I'm getting the key for the EightDProject from a textbox (SelectTrackingNumber). I'm not sure my query is working because when I look at the query result ( project ) I see the error" 'mykey' could not be resolved in the current scope or context. Make sure that all referenced variables are in scope, that required schemas are loaded, and that namespaces are referenced correctly." If the query was working I dont know how to pull the field from the distinct row it should return and put it in the textbox. I've tried the line tbPrepProbComment.Text = project.S0PrepProbSolveComment; Here is my code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.Objects;
namespace EightD1
{
public partial class Page1 : System.Web.UI.Page
{
public int mykey;
public string comment;
public object obj;
// the entity framework model
EightDdbEntities EightDP = new EightDdbEntities();
protected void Page_Load(object sender, EventArgs e)
{
SelectTrackingNumber.Focus();
}
//When the project id has been selected get projectdata and bind to page data holders
protected void SelectTrackingNumber_TextChanged(object sender, EventArgs e)
{
BindData();
}
private void BindData()
{
try
{
mykey = Convert.ToInt32(SelectTrackingNumber.Text.ToString());
}
catch
{
mykey = 0;
}
ObjectQuery<EightDProject> project = EightDP.CreateQuery<EightDProject>(
"SELECT DISTINCT p FROM EightDProjects AS p WHERE p.EightDID = mykey ");
//tbPrepProbComment.Text = project.S0PrepProbSolveComment;
}
}
}
How can i insert,update and delete records using entity framework data model.
View 1 RepliesI'm working on a new project where I have the luxury of working from a Model to Database approach using Entity Framework 4.
The project I'm working on is taking an agile approach where different phases will be rolled out over time.
Will the Model First approach work in my case? I noticed when you "Generate Database from Model" it recreates the entire schema from scratch which will obviously wipe all the data that is in the db. I was hoping for a more "Update Database from Model" approach where the db would just be altered to reflect the changes rather than recreated
I am using Entity framework to model my database (model first) however the table generator is creating tables with plural names. I have looked into the ssdltosql10.tt file. It is generating the table names from Entity set. Any way this can be changed to get the table names from "Entity Name" instead of the "Entity Set Name" so I end up with singular table names.P.S. BTW in Northwind Database the tables are pluralized however in adventure works database the tables are singular. I prefer singular.
View 1 Repliesrecently i've studied on ADO.NET's Entity Model Framework and say 'wow' as ORM is one of the fevourite pattern i practice..but suddenly i've come to an ambiguous situation when i'm going to start. i usually follow the following 3-tier architecture..
1. UI Layer
2. BLL - business logic layer
3. DAL - Data Access Layer
a. DTO / DAO
b. Gateway (contains the sql query/stored procedure and connection with DB)
now when i'm going to use the Entity Model Design,where the DBML/ .edmx File should be placed? Because many a times i'm using the DBML file as DTO because of the mapped objects.. in the same time, sometimes DBML ( .edmx file in .NET 4.0) contains CRUD methods and stored procedured method as well as methods with different selection operations,- which should be in Gateway. so where the .edmx file should be placed !?!! IN DTO namespace !? or in Gateway namespace!
moreover sometimes there is no need for the BLL which breaks the rules of inter-layer-communication (UI > BLL > DAL.Gateway)! what makes me confuse is, what should be the ideal n-tier architecture when i'll use the ADO.NET Entity Model Design Framework
I've just created a new MVC 2 application that references both an entity model library and a services library, and all compiles fine without running the app, but when I try running it, I get the following runtime error"
Compiler Error Message: CS0012: The type 'System.Data.Objects.DataClasses.EntityObject' is defined in an assembly that is not referenced. You must add a reference to assembly 'System.Data.Entity, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.
I have double checked umteen times (e.g. Umpteen*n) and the cited assembly is refenced in all three projects. If it wasn't, WTF would I not get a build error?
I am trying to configure Entity Framework 4 in the Web.config file using this ConnectionString
[code]....
I would like remove the "*" and add the actual path for my dll file.
How to find the path for a dll in Visual Studio with no add-on? (I am pretty new in .net)
ive tried to build some base project with above technologies. I wanted maximum flexibility and testability so i tried to use patterns along the way to make this as a base for future projects. However, it seem.something is wrong or whatever and i really need help here. So
i have two questions :1- Is there anything wrong with my current code ? Ive applied patterns correctly ?
2- Why do this code actually connect to the database, create it, but doesnt support insert even if i perform the corrects operation ? (Look at the end of the post for details about this error)
I have two entities : Comment and Review
COMMENT [Code]....
REVIEW[Code].... I built up a base repository for each of them this way :GENERIC REPOSITORY[Code]...For specific operations, i use an interface :[Code]....So i am getting the generics operations from the abstract class plus the specific operations :[Code]....As you figured out, i also use a database factory will produce the database context :DATABASE FACTORY [Code]....DISPOSABLE (Some extensions methods...)[Code]....DATABASE [Code]....And to finish, i have my unit of work....UNIT OF WORK[Code]....I also binded using Ninject the interfaces :NINJECT CONTROLLER FACTORY [Code]....however, when i call in the constructor ...[Code]....
This seem to create the database but doesnt't insert anything in the database in EF4. It seem that i may figured out the problem.. while looking at the database object.. the connection state is closed and server version throw an exception of this kind :
ServerVersion = '(((System.Data.Entity.DbContext (_database)).Database.Connection).ServerVersion' threw an exception of type 'System.InvalidOperationException'
I am doing the right things ? Is there anything wrong in what ive built ? Also if you have recommandation about the code i posted, i would be glad. I am just trying to the learn the right way for building any kind of application in MVC 3. I want a good a start.
I use :
- Entity Framework 4 Code-First CTP 5
- ASP.NET MVC 3
- Ninject as DI Container
I want to be able to update a model and all its collections of child objects in the same view. I have been referred to these examples: http://haacked.com/archive/2008/10/23/model-binding-to-a-list.aspx and http://blog.stevensanderson.com/2010/01/28/editing-a-variable-length-list-aspnet-mvc-2-style/ .
For example, I have an object Consultant, that has a collection of "WorkExperiences". All this is in an Entity Framework model. In the view, the simple properties of the Consultant object is no problem, but the collection I cannot get a textbox to show up for. I tried following the examples in the links above, but it doesn't work. The problem is, in those examples the model is just a list (not an object with a child list property). And also, the model again is an EF model. And for some reason that doesn't seem to work as in those examples.
[Code]....
This stuff with the EditorTemplate works fine in Phil Haack's sample project, which I downloaded to try, but here, with the EF model or whatever the problem is, I don't get any textbox at all. The table in the view is just there as a test, because in the table I do get the rows for WorkExperiences, whether I add an empty WorkExperience object or fill out its properties doesn't matter, the rows show up for each object. But again, no textbox...
I am new to entity framework , it is really very good , but I want to know what is the difference between using entity framework with stored procedure or without stored procedure , which one the faster and what is the benefits for using stored procedures with entity framework.
View 1 RepliesI have an EDM, it includes the entities extension and history. My goal is to use history to keep track of all the changes made to extension entity. For example, if extension with ID 223 has its property 'Name_Display' changed - I want the history entity to record this.
I'm using ASP.NET with VB.NET. Where in my code do I put the hook to say, "update the history entity" and what should that hook look like?
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.
[Code]....
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?)
We are developping with .net framework 2.0 on our dev station and we deploy on web server and client desktop a 3 tiers smart client app. what is the impact of ugrading to .net framework 2.0 sp2 on our web servers WITHOUT upgrading on dev station and compilation servers?
View 2 RepliesI get an cast exception when i am trying to insert an entity in Entity Framework (using code-first). From this code :
public virtual T Insert(T entity)
{
return Context.Set<T>().Add(entity);
}
The cast exception is like "impossible to cast ...Collection'1(Entity) to type (Entity)" I can't figure out why. I am pretty sure ive done everything right. Post entity
public class Post
{
public long PostId { get; private set; }
public DateTime date { get; set; }
[Required]
public string Subject { get; set; }
public User User { get; set; }
public Category Category { get; set; }
[Required]
public string Body { get; set; }
public virtual ICollection<Tag> Tags { get; private set; }
public Post()
{
Category = new Category();
if (Tags == null)
Tags = new Collection<Tag>();
}................................
I am mapping a stored procedure to an entity by right clicking on the entity (in the .edmx) and selecting "Stored Procedure Mapping." This brings you to a Mapping Details - "Name of Entity" Window that allows you to select the insert, update, and delete stored procedures associated with the Entity. It also maps the stored procedure parameter to the Entity "Property" (Column).
I'm gettin an error "error 2042: Parameter Mapping specified is not valid." The cause of the error is fairly obvious, in the Insert stored procedure that has been selected, a 'CHAR' parameter is being mapped to an Int32 Entity Property. I altered the stored procedure parameter to match the entity, I deleted the stored procedure, readded, and reslected it as the Insert function. I also cleaned, validated, updated model from database. No matter what I do, the parameter list in the mapping details doesn't reflect the change to the stored procedure. It's stuck on a char --> int32 mapping, even though it has been changed, like it's buried deep in meta data some where.