Hello everybody
With EF4, i can map a EDMX function (with "update model from database" and add a stored procedure from the list) to a linq method by using a small snippet like this
[EdmFunction("MYPROJECT.Store", "Foo")]
public Decimal Foo(Int32 Id)
{
throw new NotSupportedException("Not direct access possible, use with E-SQL or LINQ");
}
But this seems not working with EF 4.1
I see that stored procedures don't work with Code First.
I'm using DbContext, is it normal that i can't do that ?
If yes, how can i make my stored procedures working ?
Thank's by advance :-)
This is only EDMX related feature and you can't use it with DbContext API code first / fluent API without EDMX. Btw. you mean SQL function and not stored procedure because imported stored procedure results in function import and cannot be called in Linq query. Methods marked with EdmFunction states either for imported SQL functions and model defined functions.
Yes I know, SQL functions appears under the stored procedures branch in the import wizard but that is just "feature" of EDMX designer.
Because you are using database-first with DbContext API and EDMX file you should be able to use EdmFunction without any problem. I just tested it. The problem probably is that your proxy method marked with EdmFunction attribute is not static - it must be static.
Related
I'm new to Entity Framework and have ran into a problem.
I have created a stored procedure in the DB (in SMMS) and triggering from .NET works fine.
However I would like EF to feed the SP to the database if the DB is wiped (like the seed method fills in data). Also I would like to have my SP in vertion control with the rest of my codebase.
So, how do I add the SP to my project in a way that it will be created with the DB, I guess its like a migration, but with no direct connection to a model class.
Is it possible to generate a "empty" migration and then modify it to my needs? with up and down method that creates and removes the SP?
Yes it is possible to generate an empty migration and then modify it to your needs. In package manager Add-Migration "AddMyStoredProcedure"
Then in your Up method:
Sql(#"EXECUTE('CREATE PROCEDURE MyStoredProcedure...etc ");
And in your Down method:
Sql(#"EXECUTE('DROP PROCEDURE MyStoredProcedure')");
I tend to use the Sql method, but there are also CreateStoredProcedure and DropStoredProcedure methods in the DbMigration class that you may prefer
I need help using functions using Entity framework.
I have table valued function in databse on SQL server.
I am trying to add the function into edmx, but id does not show me that function.
It shows only stored procedure, but no functions when I click on Update model from database.
How can I import or use the functions using EF ?
I think Answer to your Question is already in StackOverflow.
There is no built in support for SQL User Defined Functions in Entity
Framework, your best approach would be to create a stored procedure
which wraps the function call and returns its output, then add that
procedure to your EF model.
I am working on a project using entity framework code first approach, I have a situation where I need to call a stored procedure which returns multiple table, hence I want to map the result to my model. please tell me if its possible to do it and if yes then how can i do it.
Code First currently only supports mapping to tables. This unfortunately means
that you can’t map Code First directly to stored procedures, views, or other database
objects. If you are letting Code First generate a database, there is no way to
create these artifacts in the database, other than manually adding them once Code
First has created the database. If you are mapping to an existing database, there
are some techniques you can use to get data from non-table database artifacts.
i am also facing the same problem and not able to get any solution, so i called stored procedure using ExecuteReader and then mapped it to models using autoMapper.
Let me know if you are looking for code
Actually, I have code that uses Entity Framework 4.1 in Visual Studio 2010. Everything is working fine except for one thing : it doesn't seem to "prepare" the parameters like a good old [parameters.Add] habitually did.
Here's my code :
using (MyEnterprisesEntities dataContext = new
MyEnterprisesEntities(entityBuilder.ToString()))
{
dataContext.CompanyInitializer(connection.Catalog,
args.CompanyId,
args.CompanyName);
}
So, if my company's name is O'Brian and sons (actually it passed before through a WCF web service so it's more in this form: O\'Brian and sons), it's seem to break my stored procedure (including the possibility of allowing SQL injection).
Is there a way to avoid this situation with EDMX or the old way is more reliable ?
You shouldn't not need to do anything prior to the call to your Stored Proc.
To help you, start the SQL Profiler to see what are the parameters sent to your database.
I ran some tests and if I'm using a parameter like O'Brian, the framework automatically double the quote in the query to SQL.
Is it true that you cannot call an sp with the EF unless the sp returns an entity?
To test I created 3 Function Imports for an sp with 1. no return type 2. a scalar return type and 3. an entity return type
then when i type "DataContext" then "." I only get intellisense on the function that returns an entity!
I'm surprised this isn't a current feature!
What are people using as a workaround?
There is a workaround!
Julie Lerman wrote a post about this. Have a look at her blog: http://thedatafarm.com/blog/data-access/implement-select-stored-procedures-that-return-miscellaneous-data-in-ctp2-of-ef-designer/
It helped me a lot to implement my stored procedures.
Has to return an entity, yes.
Using powerful T4 templates
Entity Framework V1.0 feels and is an unfinished product set out to public too early. That's why it's possible to use T4 templates that create different code from EDMX files, that also supports scalar-type stored procedures.
We're using custom templates with lots of modifications so they create Business layer objects, interfaces for IoC/TDD as well as DAL and DAO. We get everything from EDMX files. Heck we even create enums but those are created from real data in the DB not EDMX files.
You'll be able to find lots of T4 templates...
Here's one that does scalar stored procedures. But you may want to get one that actually does POCO.
In EF v1 you can only map procedures which return entities. In EF v4 you can map procedure results to complex types, so most procedures can be used without returning entities.
Use Chrigl's answer (+1) as a workaround for v1.