ADO.NET :: Entity Framework Dynamic Model (change At Runtime)
Mar 18, 2011
I 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.
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Jun 11, 2010
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[Code]....
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[Code]....
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Jan 6, 2011
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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;
}
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}
}
}
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Feb 10, 2010
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{
return
(from i in _dataContext.ForumPostSet
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}
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{
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}
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{
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{
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}
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}
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{
return
(from i in _dataContext.ForumPostSet
.Include("ChildPosts")
where i.ForumPostID == ForumPostID
select i).First();
}
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Nov 22, 2010
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public class Emp
{
public int CD{get;set;}
[code]...
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I developed MVC application. Then successfully import my local database which was stored in App_Data folder to the hosting provider (thanks
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[Code]....
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Nov 3, 2010
I have found some information regarding this but not enough for me to understand what the best practice for is for this scenario. I have your typicaly TPH setup with an abstract base class "Firm". I have several children "Small Firm", "Big Firm" etc inheriting from Firm. In reality I actually have different realistic classifications for firms but I am trying to keep it simple in this example. In the database as per TPH I have a single Firm table with a FirmTypeId column (int) that differentiates between all these types. Everything works great except I have a requirement to allow a user to change one type of firm into another. For example a user might have made a mistake when adding the firm, and would like to change it from Big Firm to Small Firm. Because entity framework does not allow exposing the discriminating database column to be exposed as a property, I don't believe there is a way to change one type into another via EF. The way I see it I have two options:
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I've seen a post where people suggest that One of the tenets of OOP is that instances cannot change their type. Although that makes perfect sense to me, I just don't seem to be able to connect the dots. If we were to follow this rule, then the only time to use any kind of inheritance (TPH/TPT) is when one is sure that one type would never be converted into another. So a Small Firm will never become a Big Firm. I see suggestions that composition should be used instead. Even though it doesn't make sense to me (meaning I don't see how a Firm has a Big Firm, to me a Big Firm is a Firm), I can see how composition can be modeled in EF if the data is in multiple tables. However in a situation where I have a single table in the database it seems it's TPH or what I've described in #1 and #2 above.
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Feb 4, 2010
Using a very run-of-the-mill database, with identity int for primary keys, a Dynamic Data Entities Project (EntityFramework) displays the primary key for view and edit. When using Linq to Sql, the primary key fields are not displayed.
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Oct 3, 2010
I have an asp.net dynamic data website .net 3.5 built on ado.net entity framework with mysql database.Currently I have just one table in my entity model.
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Nov 29, 2010
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.
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Dec 25, 2010
recently 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
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