1 (mvc3) I have added a stored proc to my model as mapped to a ComplextType.
Two Issues:
1) ComplextType.cs exists in class under Model1.tt BUT doesn't show up in .edmx?
2) When I try to create a controller with strongly typed views with that ComplexType.cs it errors stating that it can't be created because ComplextType.cs is not part of the DbContextEntities class?
How can I get this complex type added to the .edmx and mapped to my dbcontext (I have done this with tables but not sure what I'm missing for the stored procedures?
Thanks!
For those who just came here from googling,, :)I will give the what is basically has to be done to map a stored procedure into a ADO.Net entity.
When mapping the Database to the EDMX file(Entity Model).. the Entity Model automatically map the tables and complex types and ect.. But the stored procedures that are created in the database is not mapped with return complex types. We have to map it in the Function imports by creating our own complex type. This complex type can be accessed in the code.
This is done as below:
Right click on the function Import and add new Function import.
Give your name to the function and specify the stored procedure and
then select complex type(If stored procedure returns complex type)
or you can select scalar. IF you are selecting the complex type and
you can view the columns that are returning and you can create a complex there by create new complex type.
So the return data from the stored procedure will be a set of those complex type.
One thing that should be one should access the design or the model view to update the Entity Model. You can not update the Entity Model by just right clicking on the Entity Model. The option of updating the model is provided only on the Model Browser and the Database design diagram. This model browser can be taken from the Other windows of Views in VS2010/VS2012. These information will seems boring. But trust me if you are new to this these seems big at the beginning.
Most probably you are going to create this Entity Model from mapping an existing database.
Keep in mind that even you map the Entity model form the database you can customize the Entity model by deleting the unnecessary entities(tables) and creating complex types
Related
I'm having a few tables on SQL Server, which have similar structure - int Id and string Value.
This tables linked to main table via foreign key, so I'm wrote a bit of logic for mapping a string values to id's in models in MVC Razor. This feature requires that models used as dictionary implement simple IKeyValue interface with Id and Value, but after updating model from database I can loose interface implementation from models and must write it again.
Any way to automate this?
Are you modifying the auto-generated file? If so, you should not do this, for the exact reason you describe in your question -- it will get overwritten.
All of the classes in the generated file should be partial. You can take advantage of this by creating another class (in a different file, but in the same project), make sure it has the same declaration (and namespace), and have it implement the interface. This way the class will implement the interface, but will not be overwritten the next time you refresh the schema from the database.
I am currently working on a project where we are rewriting software that was originally written in Visual DataFlex and we are changing it to use SQL and rewriting it into a C# client program and a C#/ASP.Net website. The current database for this is really horrible and has just had columns added to table or pipe(|) characters stuck between the cell values when they needed to add new fields. So we have things like a person table with over 200 columns because stuff like 6 lots of (addressline1, addressline2, town, city, country, postcode) columns for storing different addresses (home/postal/accountPostal/ect...).
What we would like to do is restructure the database, but we also need to keep using the current structure so that the original software can still work as well. What I would like to know is would it be possible using Linq to write a DataContext Object Model Class that could sort of interpret the data base structures so that we could continue to use the current database structure, but to the code it could look like we where using the new structure, and then once different modules of the software are rewritten we could change the object model to use the correct data structure???
First of all, since you mention the DataContext I think you're looking at Linq to SQL? I would advice to use the Entity Framework. The Entity Framework has more advanced modeling capabilities that you can use in a scenario as yours. It has the ability to construct for example a type from multiple tables, use inheritance or complex types.
The Entity Framework creates a model for you that consists of three parts.
SSDL which stores how your database looks.
CSDL which stores your model (your objects and the relationships between them)
MSL which tells the Entity Framework how to map from your objects to the database structure.
Using this you can have a legacy database and map this to a Domain Model that's more suited to your needs.
The Entity Framework has the ability to create a starting model from your database (where all tables, columns and associations are mapped) en then you can begin restructuring this model.
These classes are generated as partial so you could extend them by for exampling splitting the database piped fields into separate properties.
Have you also thought about using Views? If possible you could at views to your database that give you a nicer dataschema to work with and then base your model on the views in combination with stored procedures.
Hope this gives you any ideas.
I have three views that I've manually created in the DB.
First view is "Region", the second is "FIPS" and the last is a many-to-many between them called "Region2FIPS". These are all views, and I only need read access the data, so I'm not worried about having updateable views.
I have added each of these views to Entity Framework, and created the appropriate associations between them.
Region to Region2FIPS is a 1 to many.
FIPS to Region2FIPS is a 1 to many.
The "Region2FIPS" view contains only two columns, one called "FIPSID" the other "RegionID". These column are associated with their respective views in the relationships I defined above.
When this type of association is made on tables in the DB, Entity Framework knows that it is a many-to-many relationship and it creates a navigation property on "Region" called "FIPS" that I can use to navigate through the child collection of FIPS. It does likewise for "FIPS" to "Region".
However, when done manually, with views, it does not exhibit that behavior. Instead, my "Region" object has a collection of "Region2FIPS" objects, which each have a navigation property called "FIPS" which is of type "FIPS". And my "FIPS" object has a collection of "Region2FIPS" objects, which each have a navigation property called "Regions" of type "Region".
I assume this has something to do with the fact that I can't create foreign key references on the views, so entity framework doesn't realize the many-to-many relationship. But I thought that if I manually created the many-to-many relationship between the views it would recognize it and properly handle the navigation between the types. Is there a way for me to force it to do this?
It's possible, but the designer doesn't really help you here. You have to do the mapping manually.
One fairly easy way is to use Code First mapping. But this means your model has to be Code First to begin with. If you're writing a new model, just do that.
If you're using DB First mapping, however, you will have to do the mapping manually. Your SSDL will probably already be correct, once you define the "primary keys" of the views. You would then have to remove the "Region2FIPS" objects from the CSDL (not just from the designer!) and manually patch up the MSL.
Perhaps the easiest way to do this would be to use the designer to automatically map real DB tables (not views) with a similar schema and then replace the table names with view names in the EDMX, using the XML editor.
I’m having a philosophical problem with understanding how to use Models on MVC3.
I believe the problem lies from the fact that I come from WebForms :--)
Let's say I have 10 tables on my DB and as expected when I get them into my EF4, I get those Entity classes that represent the tables (and all their FK integer values).
When I want to display data on the View, I cannot display a select * from table because those FK integers means nothing to my users …and also because some data lies on related tables.
So my understanding is that I can create a Stored Proc, create a Complex Type that represent the actual data to display, coming from separate tables via different SQL joins.
QUESTION 1:
On the view, id MVC compliant to use as #model ..that Complex Type?
or shall I always use Models that are created on the Models folder? And if so, does that mean that I have to replicate the Complex Type on a new model inside the Models folder?
Question 2:
Is this the right way …to create specific SP to collect data that will be displayed or ..is it better to use linq and lambda to be applied to the EF4 Types that come from importing the DB into the EMDX designer.
Thoughts ??
FP
The correct way is to always define view models. View models are classes which are specifically tailored to the needs of a given view and would be defined in the MVC application tier. Those classes would contain only the properties that would be needed to be displayed by the view. Then you need to map between your domain models (EF autogenerated classes?) and the view models.
So a controller action would query a repository in order to fetch a domain model, map it to a view model and pass this view model to the view. Top facilitate this mapping you could use AutoMapper. A view shouldn't be tied to a domain model and always work with a view model. This works also the other way around: a controller action receives a view model from the view as action argument, maps it to a domain model and passes this domain model to the repository in order to perform some action with it (CRUD).
So a view model could be a class that is mapped from multiple domain models or multiple view models could be mapped to a single domain model. It all depends on how your domain looks like and how do you want to represent the information to the user.
As far as validation is concerned, I distinguish two types: UI validation and business validation. As an example of UI validation is: a field is required, or a field must be entered in a given format. A business validation is : the username is already taken or insufficient funds to perform wire transfer. UI validation should be done on the view models and business validation on the domain models.
I'm not sure why you need to use a stored proc, LINQ to Entities is able to generate complex types without needing to create stored procs (in most cases). You select subsets of data, just like you would with regular SQL.
As Darin says, the use of a View Model is appropriate for situations where you have a lot of complex data that isn't represented by a single entity. This View Model would contain multiple entities, or even multiple collections of entities. It all depends on how your data needs to be consumed.
I'm using stored procedure in LINQ, i know it will generate a class T(procedure name + "Result") for me automatically to store the data.
If the name of stored procedure is spCampus, the generated class will be spCampusResult.
My Question:
when i'm using SP should i create custom class that replicate all the properties ( i'm refering to whatever the .dbml creates when you drag and drop the SP)
in my situation i will be using SP... is that fair to say i will be treating as a class object and pass around from model to controller and to view ?
or i will be better off creating a new custom business object contining all the props from .dbml ?
i havent get any clear cut answer
anybody?
In the designer you can shape the object any way you see fit. You can change the names of the properties you can change the name of the object returned from the sproc if you want to. It is also my understanding that you can change the protection levels on the properties as well. This to me means that you can use the LINQ2SQL generated objects as your DTO's or you business objects because you have the power to shape them as you see fit in the designer and since they are partial classes you can extend their behavior without touching the generated class. Hope this helps.