Entity Framework 4 - Update Database Schema From Model. Without Wiping The Table Data?
Jun 29, 2010
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
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.
When adding a stored procedure into the Entity Data Model I can select whether the procedure returns a scalar, a (new) complex type or one of the entity types I already defined.I mean assuming I have a view like this
CREATE VIEW FilteredFoos as SELECT Foo.* FROM Foo join ... WHERE ...(that is a view that implements some involved filtering, but returns all columns from one table) how do I add it to the project so that I can use the entity set, but get the Foo objects, not some new FilteredFoo objects.
var foos = myDB.FilteredFoos.Include("Bar").ToList(); foreach (Foo foo in foos) { ...
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.
I am using LINQ to SQL with C#. Is there a method through which we can generate entity class files from the table schema? By dragging tables onto the graphical designer classes are generated but they are not the real class files(i mean actual files with the extension cs).
I am aware of that we can code the class files first and then create the schema manually or programmatically, but i wanted to know if the reverse is possible, may be using some third-party tools. I feel it will be very convenient to use LINQ that way.
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 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?
I'm using Entity data model to reflect my database and I generate Domain service from my Entity data model.I understand that if I have changes in my database, I can just choose "Update Model from Database", but there is no "Update Domain service from Model" option available.How should maintain my domain service? I'm not going to delete away it and regenerate it whenever there are some changes, right?
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
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.
i 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.
i have the following code where I want to retreive the data form a table using entity framework and put it to a list of the same type:
List<ItemDetail> iDets = new List<ItemDetail>();
iDets = (List<ItemDetail>) from l in db.ItemDetails where l.ItemID == varItemID select l;
when I run the page, it throws the following error:
Unable to cast object of type 'System.Data.Objects.ObjectQuery`1[LIBRIModel.ItemDetail]' to type 'System.Collections.Generic.List`1[LIBRIModel.ItemDetail]'.
why i'm having this problem? or am I missing something here if i'm not wrong it worked once, but now it throws this error
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.
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)
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.can someone give me any example that connects to a sample oracle database and use LINQ to oracle
I'm writing a custom .NET MembershipProvider (not the built in one) and trying to update using Entity Framework. But of course i have no access to (Try)UpdateModel. How can i update it?
