I have a table in my database called "Task". Task has the following fields:
- ID
- Description
- AssignedUserID
- TaskTypeID
I am accessing this table through a class that was created automatically after I used an ADO.NET Entity Data Model. I can load and show the fields mentioned above in a DataGrid in my Silverlight application. However, AssignedUserID and TaskTypeID are not very descriptive. So I decided to create a stored procedure that gets the tasks and the user and task type names through their respective lookup tables. This is where the problem lies.
I want to create some custom properties in the automatically generated "Task" class. The custom properties would be named "AssignedUserName" and "TaskType". I then want to make these properties available to my Silverlight client. However, I cannot seem to figure out how to get them exposed to my Silverlight client.
Can someone help?
Thank you
If your EDM is in the same project as the DomainService you can do this:
create a partial class on the Entity type, and add your calculated property in there.
name the file **.shared.cs
it will then be auto-shared with the client/Silverlight code.
Edit:
I was assuming that you could do this calculation in app logic rather than use an sp, which seems more straightforward to me.
If you do use an SP, you'll need to use the Function Import feature in the designer to map the SP to a function in the EDM. This function can then return entities, with properties mapped however you like.
An easier way would be to just use the object model: Have Task.AssignedUser and Task.TaskType objects off of your Task class. Map these to lookup tables in your db. This will work out-of-the box (assuming the Id's are FK's to those lookup tables).
So, a couple options:
use app-logic--properties in a partial class to return the descriptions
use the object model driven by FKs to lookup tables, then just access Task.AssignedUser.Name or Task.TaskType.Description
use a function import to access the SP and map the returned values to entity properties
1 or 2 being the best options IMHO.
Another approach might be to update your EF model to include the lookup tables, add Associations between the tables, add [Include]s in the (auto-gen'd) metadata class and let EF and RIA do it for you. Maybe.
Related
I'm attempting to create an instance of the Forge-viewer API to reference an outside database (Homemade, not bim360 or Fusion) as the Properties of an object selected. (i.e. the database parameters fill-in the properties window) However, I'm unable to find a method. What do you recommend?
The best place to start would be the below code samples:
https://forge.autodesk.com/blog/adding-custom-properties-property-panel
https://github.com/yiskang/forge-au-sample/tree/master/properties
https://github.com/Autodesk-Forge/forge-rcdb.nodejs //interaction with custom data source and many data centric plugins
Basically you will need to customize the model property panel and feed in your own data source by extending Autodesk.Viewing.Extensions.ViewerPropertyPanel and setProperties/setNodeProperties ...
This one is making me crasy : I have an EF model built upon a database that contains a table named Category with 6 rows in it.
I want to display this in a drop down list in WPF, so I need to bind it to the Categories.Local Observable collection.
The problem is that this observable collection never receives the content of the database table. My understanding is that the collection should get in sync with the database when performing a query or saving data with SaveChanges() So I ran the followin 2 tests :
Categories = _db.Categories.Local;
// test 1
Debug.WriteLine(_db.Categories.Count());
Debug.WriteLine(_db.Categories.Local.Count());
// test 2
_categories.Add(new Category() { CategoryName = "test" });
_db.SaveChanges();
Debug.WriteLine(_db.Categories.Count());
Debug.WriteLine(_db.Categories.Local.Count());
Debug.WriteLine(_categories.Count());
The test 1 shows 6 rows in the database, and 0 in local.
The test 2 shows 7 rows in the database, and 1 in local (both versions)
I also atempted to use _db.Category.Load() but as expected, it doesn't work because it is db first, not code first.
I also went through this page https://msdn.microsoft.com/en-us/library/jj574514(v=vs.113).aspx, created an object-based data source and linked my combo box to it, without success.
Does anyone know what I am doing wrong?
Thank you in advance for your help.
The DbSet<T> class is IQueryable<T>, hence DbSet<T>.Count() method maps to Queryable.Count<T> extension method, which in turn is translated to SQL query and returns the count of the records in the database table without loading anything into db context local cache.
While DbSet<T>.Local simply gives you access to the local cache. It contains the entities that you added as well as the ones being loaded by query that returns T instances (or other entities referencing T via navigation property). In order to fully load (populate) the local cache, you need to call Load:
_db.Categories.Load();
The Load is a custom extension method defined in QueryableExtensions class, so you need to include
using System.Data.Entity;
in order to get access to it (as well as to typed Include, XyzAsync and many other EF extension methods). The Load method is equivalent of ToList but without overhead of creating additional list.
Once you do that, the binding will work. Please note that the Local will not reflect changes made to the database through different DbContext instances or different applications/users.
I am working through the ASP.net Web API 2 book (Git Hub)
I am trying to use Fluent NHibernate and Automapper to connect to a database. The book uses a fresh database while my database is pre-existing and not necessarily controlled by good practices.
Before joining tables etc. I would like to just be able to get a list of people and add a new person via the API. The only catch is that I would like to return less properties of the actual table and create a new person with even less than the model used to display a new person. I am having trouble understanding the flow of the automapper.
An example table might be
<pre>Person Entity
-person_id(int)
-person_name(varchar(100))
-person_location(int)
-person_phone(varchar(10))
-person_address(varchar(30))
</pre>
The model I want to use includes a subset of the items in the actual table. For example, maybe:
<pre>Person Model
-person_id(int)
-person_name(varchar(100)
-person_location(int)</pre>
There is also a newPerson model
<pre>NewPerson Model
-Name
-location</pre>
I have an Entity with all the person properties like
public virtual int person_id {get;set;}
but I have a model with the subset properties like
public long person_id {get; set;}
In the automapping configuration file I have a class NewPersonToPersonEntityAutoMapperTypeConfigurator and I have another class PersonEntityToPersonAutoMapperTypeConfigurator
I'm confused about how automapper is working. Should the AutoMapper file NewPersonToPersonEntityAutoMapperTypeConfigurator use something like
Mapper.CreateMap<NewPerson, PersonEntity>
.ForMember(opt => opt.person_id, x => x.Ignore())
...
.ForMember(opt => opt.person_address(varchar(30)))
While
PersonEntityToPersonAutoMapperTypeConfigurator uses something like
Mapper.CreateMap<PersonEntity, PersonModel>
Can anyone show me a good example of a simple scenario like this with automapper and a pre-existing table with extra unused properties or describe what Automapper should be doing or if I am on the right track?
Daniel - I think you're on the right track. Yes, you need an AutoMapper map for each "direction"... i.e. incoming service message to the EF entity, and from the EF entity to the service return message.
Your code to ignore certain properties is fine. You just need to make sure the entity is populated appropriately for the INSERT into the database. For example, the person_id column - is that required to be set? Or is that an auto-incrementing column??
To say it another way... you can certainly use AutoMapper (and our approach in the book) against an existing database. It's still just mapping properties from one type to another type.
Feel free to send some code my way.
I would need an idea or two how I would do this in cakephp (using latest version)
I am building a web based game where you will be able to collect Items
Without a framework I would have an abstract base item class that every item would extend to
And when displaying for example a inventory i would factory all items the user currently have and then return a object for each item.
classes...
BaseItem
WeaponItem
HealingItem
etc..
How would I do this in cakephp? Would I go for a model for each item class ... and how would i factor to get the object? ...
Assuming you're using a database as the data store, presumably you will use a single table for all items the player can collect? If so, you probably want a single Model class.
It's possible to have an inheritance hierarchy for models in CakePHP if you want. But you can often achieve sharing of Model logic using a Behaviour.
I want to use the database access objects to access a table in my database instead of doing active record since that takes a long time to load. if I use database access objets instead (calling createCommand, query, execute, etc), do i still need to create a model class for the table? if so what would be the parent class of this model class? My goal is to access/edit the table values using yii database access objects. I'm using YII FRAMEWORK. Or is it best to use a component? If so, when do you usually have to use components? I don't understand what components are for....
No, you can create a generic class which has a member property of a CDbConnection. For that matter, you can just use CDbConnection, but you might end up creating a lot of connections that way.
class Foo
{
private $conn;
function __construct(){ $this->conn =
new CDbConnection($dsn,$username,$password); }
function runQuery($sql) {
$command=$connection->createCommand($sqlStatement);
return $command->query();
}
}
If you have your database settings in your config/main.php file, you can also do:
$command = Yii::app()->db->createCommand($sql);
$result = $command->queryAll();
and if you need to reset the command:
$command = false;
If you create a custom class, you don't need to reference a Model or extend an existing class, your connection will use CDbConnection (by using the method above or calling it directly in your connection statement).
this page has pretty clear info on Yii's DAO.
As far as components go, they can mean different things - there are Yii's "core components", which are things like urlManager, user, db, etc. and can have their default properties set in the config/main.php file. Then there is the "components" directory which can be configured to autoload classes and "contains components (e.g. helpers, widgets) that are only used by this application." So you can put custom classes in there that you want available throughout your app.
Components are used to make widgets.which is available through out the app.