how to change the database while using ADO.Net Entity Framework?
I have two identical databases. I want to change the db. Can i change it through web.Config?
Like LINQ to SQL ?
I have a stupid problem with the Entity Framework. I get the following Exception:
[Code]....
I have an entity with a 4 fields representing the primary key. I copy it via serialization (works fine). I set the old entity to not valid (Datefield set to a date in the past, this field is part of the PK) and set the copied entity to DateTime.Now.Date. When I call context.AddObject I get the Exception above. I tried copying the entity via reflection but the entity has 3-4 references. And when copied, I get another Exception before even Adding the entity to the context. I also tried setting newObj.EntityKey = null and reset all the fields neccessary for the PK. I just want a whole copy of an entity with a different primary key (and some other fields changed too) and Create it in the database.
Is there any way of tracking EF entities changes between contexts for ASP.NET applications?
Self-Tracking entities doesn't work well for me as it is primarily designed for WCF. And all approaches for tracking changes for POCO I have found are oriented on shared context.
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:
Don't use TPH. Simply have a Firm Entity and go back to using .Where(FirmTypeId == something) to differentiate between the types. Execute SQL directly using context.ExecuteStoreCommand to update the FirmTypeId column of the database.
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.
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.
View 2 RepliesIs 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 want to update database using entity framework by passing class object in one go with setting without setting object values again.
I have added data using following code
[code]....
here obj is class object which i have passed to the AddTotblTables() method
similary i want to update table in same manner by passing class object.
in my table test
Name Add
0 prinku sad
1 tommy asdsa
2 ghhgh sdsdd
now i want to select the name in the first row...am using Ado.net entity framework
empEntities db =
new
empEntities();
now how to select the name at 1
db.Tests.Name.ElementAt(1);?actuually this throws an error...
We have an IVR product that reads a configuration database for callflow information. I am writing a tool for our implementation team that will allow them to add/delete/update the data in the configuration database. Once the tool is in production, the implementer will use only the production release of the tool to modify the configuration database in all four of the IVR regions (Dev, QA, Cert, and Prod). Each region has its own database with identical schemas. The tool has 'tabs' across the top for each region. If a user is currently working in the Dev region and clicks the QA tab, how do I switch my connection from the Dev db server to the QA db server?
View 3 RepliesAll I am trying to do is to make an update to an existing User and then save the changes to the database. I fooled around with different options and can see that I can make the change to the context during Page_Load, but it does not commit the changes to the Database.
View 5 RepliesI need to do a site similar to [URL] but don't know how to display or retrieve the images as in the above website.
View 3 RepliesI am using ADO.NET Entity Framework 3.5 for web service.i want to know how can i caching through it and can minimize database hits?
View 1 RepliesI transfered my data from MDF files to MS SQL Database, but I can't get it working with entity framework.
My Old connection string is:
metadata=res://*/Models.EntityModel.csdl|res://*/Models.EntityModel.ssdl|res://*/Models.EntityModel.msl;provider=System.Data.SqlClient;provider connection string="Data Source=.SQLEXPRESS;AttachDbFilename=|DataDirectory|TripsDB.mdf;Integrated Security=True;User
Instance=True;MultipleActiveResultSets=True"
I put all data from TripsDB.mdf to Trips table in local MS SQL 2008 Enterprise database. Also changed connection string to:
Server=WIESIEK;Database=Trips;Trusted_Connection=True;providerName=System.Data.SqlClient;User ID=Jan J. Roman
But my application throws System.ArgumentExceptio with message: The 'server' keyword is not supported.
on line:
private TripsDBEntities2 _entity = new TripsDBEntities2();where TripsDBEntities2 is Entity Framework instance.
I am using MUSQL Database extensivly in my projects,
can we build ADO.NET entity framework based on MYSQL database?
As a follow on from this question I'm building a custom server control to be placed on a Sharepoint 2010 master page. The idea behind this is that it will display a menu that is dynamically populated from the database. As this is a server control, I'm building it in a dll but I've run into a small snag. As it has to connect to the database, I need to store the connection string somewhere (and have it able to be configured based on target configuration (dev/test/prod). I was intending to the user the Entity Framework as my ORM but i'm confused as to where the connection string is to be stored. In a normal ASP.NET web app it goes in the web.config, but this is a server control in a external DLL.
Where do I store the connection string so that I can just build and deploy the assembly containing the server control.
EDIT:
Before I post a bounty, I have tried using an embedded resource XML file to hold the connection string and while this works, I'm curious as to if this is best practice/a better way?
I have an ASP.NET application with existing business classes and a database schema. (which I would like to keep) Currently I am using ADO.NET for the DAL, but I would like to switch to some advanced technology there for easier data retrieval.
Is EF applicable to my situation? Can I use it without splitting up my business classes and auto code generation? Can LINQ to SQL solve my problem better?
All I want to do is map my existing classes to the existing tables and dont have to handle details of the data retrieval myself.
I'm working on an application that is connected to the online MSSQL database and everything is working fine.The model I'm using is entity model.The problem is that I have to change the connection string from the online database to the local one,but I don't know how.Creating new model isn't an option.I tried changing the connection string in web.config,but errors are the only thing I get.
This is what I have in web.config:
<connectionStrings>
<add name="PravosudnaAkademijaEntities" connectionString="metadata=res://*
PrakModel.csdl|res://*/PrakModel.ssdl|res://*/PrakModel.msl;provider=System.Data.SqlClient;provider connection string='Data Source=HRVOJE-PC;Initial Catalog=pak_baza;Integrated Security=True" providerName="System.Data.EntityClient" />
I have an ASP.NET Page that updates registered User Address Details for a selected record.
Below is the Update method that i am calling from Controller.
When i am calling ApplyPropertyChanges method, I am getting the below error.
Did anyone run into the same error while updating the record with Entity Framework.
[code]...
I am working with VS 2010, Entity framework, SQl-Server 2005, ASP.Net web forms. Currently, I am working on the Data access layer library which soon will be a web service, using Entity Framework collaboration with different design patterns like repository pattern and some best practices that posts in different blogs. I am also test each repository using the Unit testing project. Thumbs up! Working fine.
The thing I am worried about is, how much is good for retrieving data from a table that can contain 80-100k records ?
If I want to be able to have a table Consultant, which is the user and their personal information, and I want this user to be able to select their proficiency in a number of Programs (software) on a scale from 0-5 (zero being no experience whatsoever), how do I do this best?
I mean I could have a Consultant table with a one-to-many relationship to a Program table, and then have all the limited Programs availalbe loaded by an XML file or something, and for each Consultant associate all the Programs and their Levels of proficiency. But that seems very wrong and inefficient.
It seems to me I should have a table with all the (limited number of) Programs, and then by some sort of association between the two by Ids. But I can't get my head around how to do this. I'm thinking many-to-many... But first, is this correct? Secondly, how do I do this in an Entity Framework Model? I usually create my database code first, i.e. create the EF model, and then generate database from model. Will I get a junction table where I can add the Level field, because basically a Consultant HAS A Program with a Level, or actually a list of Programs each with a Level.
First and foremost ... I already made a few changes in the template, the most important one changing the methods generated for stored procedures with OUTPUT parameters and no resultset so that instead of instantiating a few OutputParameter objects, passing them to the method and extracting the values (all without any type checking) you just call the method with a few "out someType?" parameters so I do not need the very basics. I am totally confused by all those GlobalItem, EdmProperty,BuiltInTypeKind, TypeUsage and all this made of objects, all alike and all different though so as soon as I need more data than what's already used by the template I run into problems :-(What I would like is to change the WritePrimitiveTypeProperty() so that it outputs [StringLength(xxx)] for all char, varchar, nchar and nvarchar properties. But I can't find a way to get from an EdmProperty in the model to the database type in the store.anyone is interested here's the modified stored procedure mapping code for the template. The first code replaces the original in the .tt:
[Code]....
the second needs to be added into a copy of EF.Utility.CS.ttinclude that you add to your project and reference from the .tt
[Code]....
I want to know if I develop and application using entity framework 4.0 and sql server and then changing the connection string to my sql one, will it work without any problem?
What are the other considerations to keep in mind?
I'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 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 created two stored procedures in SQL Server Management Studio.
First procedure add field in ProjcetsToUsers table (for many-to-many associations)
[code]....
I can delete the user from the project and then add another, and the new one is added but removed the remains.
As for data base both this function work correctly.