I have 3 tables(Roles,Actions and RoleActionLinks). Roles table has few columns(RoleID,RoleName,Desc). Actions table has few colums(ActionID,ActionName,Desc). In RoleActionLink is created for store the association between Roles and Actions and this table has the columns such as RoleID,ActionID
When I created the data model(edmx). it shows only Role and Action as entity. i did not find RoleActionLink table. but even there is no direct relation between Roles and Actions table, both tables are automatically related using RoleActionLink table.
When i create the new Action, a action record should be populated in Action table(this is works fine). At the same time, i need to populate record in RoleActionLinks table. But i dont have the entity to populate.
Please tell me how to accomplish my needs.
This should work:
newAction.Roles.Add(role1);
newAction.Roles.Add(role2);
Look at navigation properties in your model. There should be EntityCollection called Roles (name may differ).
Entity framework automatically handles n-n tables and creates collections on both sides.
Related
I have an asp.net MVC solution, Entity Framework code first, which has dozens of database tables all designed around a single company using the solution.
The requirement has come up to allow multiple companies to use the solution, so what we have done is add "CompanyID" as a column to all database tables and set a default value. There is a company table with the various company names and CompanyID's. On login the user selects the company they are logging in as which stores the CompanyID in the session.
At the moment every Entity Framework call now has to be updated to include the CompanyID, for example when selecting Employees I am doing:
List<Employee> employees = db.Employees.Where(x => x.CompanyID = Session.CompanyID).ToList();
As you can see it will be tedious to do this on thousands of calls to the db. Any update, save, and fetch has to change.
Surely I am doing it the long way and there is a way at runtime, globally to append all DB calls to include the CompanyID stored in the logged in users Session? Something that dynamically appends the CompanyID when fetching values or storing etc? Perhaps a package I can use to do this task at runtime?
In my opinion, there is no need to add CompanyID to EVERY table in the database. I would select just "root" tables/entities for that. For example, Employee or Department clearly sounds like a many-to-one relationship with a company - so adding CompanyID there sounds right. But, for example, EmployeeEquipment which is a many-to-one relationship with Employee does not have to have CompanyID column since it can be filtered by the joined Employee table.
Regarding your request to filter by CompanyID globally, I'm not aware of anything that can do that per request. There are global filters for Entity Framework, but I'm not sure how you can apply them per-request. Take a look on .HasQueryFilter() during model creation if you are using Entity Framework Core.
I have a Symfony app using multiple entities.
A third-party analytic tool plugs to my database to create reportings.
What I would like to achieve, is being able to update the Symfony entity from the frontend in order to add new fields to the database tables (in order to get the new fields showing up in the reporting tool).
Anyone has a idea on how to achieve that?
Thanks in advance.
If i understand correctly, you wan't to be able to add fields to your entity dynamicaly.
I don't know if this is doable and if so, it would probably be messy and unsecure.
What you can do however is using sub-entities with dynamic key => values fields.
You should have one main entity, an entity with the list of your dynamic fields, a many to many relation between your main entity and your fields entities and a third entity with the actual values from those fields.
Let's say I have a Setting entity with some fields like IntValue, dateValue, stringValue and some linked entities, like countries (ManyToMany to entity Country), languages (ManyToMany to Language) etc.
Settings are created by users and assigned to specific objects (not important here, but I wanted to clarify).
Now I suddenly need to have UserDefaultSetting, which will be the same, but with additional user field (ManyToOne to User entity).
I tried to extend existing Setting entity class with one more field added. The problem is, as I looked at the schema update SQL, it created new table for the new entity, but without all the tables needed to ORM connections (mostly ManyToMany). Just one table with "scalar" fields.
So previously I've had setting table with int_value, date_value etc. but also setting_country and setting_language tables, linking ManyToMany relations. After creating child entity, Doctrine created only user_default_setting table with int_value, date_value etc. and additionally user_id column, but I can't see any relation/link tables.
I know I should've been do it with abstract base entity class, but at the time I started, I didn't know that and now part of the project is on production (don't look at me like that, I blame the client) and I don't want to change that "base" class now. Can I inherit everything from non-abstract entity class in a way it will work?
UPDATE: everything explained. See Cerad's comment. Thanks!
I have an Entity Data Model for my Web Site that includes a table with some extra data for the registered users (called UserInfo). Currently, I'm setting the id of the new rows of UserInfo using the Membership.GetUser(...).ProviderKey.
What I want to do is to add a navigation property to my UserInfo table to point to the corresponding Membership row for that user but, due I have not the Membership schema in my Entity Designer, I can't figure out how to stablish this link between the tables.
Any idea?
Thanks very much,
Well, I've finally decided it's easier simply to add a property to my UserInfo table (called guid) that store the guid of the MembershipUser schema.
I have created my Database which has:
Artist, tracks and TracksPerArtists
I can do sql queries through the entity model. For example when I make:
database.TRACK.ToList()
I get the list of track to be shown on index view for example. But my foreign keys come empty. While there is an artist and a track, and the correct row for ArtistsPerTrack, this item in my track.ToList() collection is empty.
Is there a different way to fetch those data?
I came from cakePHP framework in which you can define the Model.recursive property to declare the depth of the relations you want to fetch.
Is there anything similar here?
There is something similar.
If "database" is DataContext and Artist and Tracks have many to many relationship in database, you can fetch related entities using Include clause:
database.TRACK.Include("Artists").ToList()
where "Artists" is the name of property on Track entity.