I am using Fluent NHibernate 3.1.0 (with NHibernate 5.3.8) for my domain mappings. The project I am working on is targeting .NET 5. The database engine used is SQLite with the data provider System.Data.SQLite 1.0.113.7.
I am trying to find a way to apply convention for constraint names in my project. I really want to avoid names like FK_935624DA.
I cannot find the answer anywhere, but I am certain the infos is somewhere but I am overlooking! Of course I read the following (official) documentation on GitHub.
https://github.com/nhibernate/fluent-nhibernate/wiki/Conventions
I have to say that however, by example I managed to define a custom foreign key convention that way:
internal class ForeignKeyNameConvention : ForeignKeyConvention
{
protected override string GetKeyName(Member property, Type type) => type.Name + "ID";
}
Can you point me out in the right direction with a code sample or a link?
Thanks !
P.S. If I missed some infos, let me know, I am not really used to post on Stack Overflow.
Related
Hi i write because i have configured the Audit for one single table for all my entities and its working fine for the general tables in my model, but with the Many-To-Many tables i don't know how can i do for setup the "AssociationEntryRecord"? the event is fired by EF when i do one change in this tables but i don't know how saved!
Could you please help me with this questions, thanks in advance for your help & the library...
For configuring the Entity Framework event provider use the fluent API provided by Audit.EntityFramework.Configuration.Setup()
You can include the associations as follows:
Audit.EntityFramework.Configuration.Setup()
.ForAnyContext(config => config
.IncludeIndependantAssociations());
And about your sample code (what you should have included as textual code and not as an image):
The first line is not needed, since the UseEntityFramework() will
override the DataProvider
The primary key value can be calculated as: entity.TablePk = entry.PrimaryKey.FirstOrDefault().Value.ToString();
Mates, I want to update a role description using my application
I don´t know what is the better way to connect to the database and run a UPDATE statement.
Would it be Entity Framework? LINQ? None of this 2 options..
Please, suggestions.
I would say that Entity Framework would be currently the best solution for you. Not only it is strongly supported by Microsoft (well Silverlight was as well) but:
If you start with it, you can use designer. It's graphical UI will guide you when generating the model (based on database) or generating the database schema when starting with model.
Read some tutorials abut it:
http://msdn.microsoft.com/en-us/data/ee712907
And later take a look how to use some more profesionla techniques as Repository pattern or unit of work
http://www.asp.net/mvc/tutorials/getting-started-with-ef-using-mvc/implementing-the-repository-and-unit-of-work-patterns-in-an-asp-net-mvc-application
Not Linq ..well yes linq, but linq is the querying framework where as entity framework is the object relational mapper. So Both actually. You could do this in various other ways but those two technologies work very well together from my experience.
In Visual studio you would create a new ADO.NET project template which you then hook up to your database. and then you can update the tables and do a whole bunch of stuff. Linq is build into .NET so technically you can query any objects using linq ( which makes it so much fun ) and because your entity is an object you just reference it ( first declare it ) and then play with it
FooModel foo = new FooModel(); // Entity
var fooQuery = from _ in foo.DescriptionTable // Linq query
where _.Description == SelectedDesc // table selection query
select _;
foo.Add(fooQuery); // add to database
foo.SaveChanges(); // save changes
Something like that. There is a bit more to it that would project specific but you would have to give more details.
It is most certainly worth learning both technologies and have doubt you will find them very useful. Both can get very complex but for what you need it for you just need the basics down and then you can explore from there.
We are looking for a way of automatically filtering all CRUD operations by a tenant ID in Entity Framework.
The ideas we thought of were:
Using table valued user defined functions
Using stored procedures (but we don't really want to, as we're using an ORM to avoid doing so)
Some how modifying the templates used to generate the SQL to add a where clause on each statement.
Some how modifying the templates used to generate the LINQ in the controllers (we may use MVC).
Any tips?
-thanks
Alex.
Using table valued user defined functions
Table valued function are only available in .NET 4.5 Beta (and not available in code first). Using them will still not help you because you will have to use the function in every LINQ query so it is the same as using where clause.
Using stored procedures (but we don't really want to, as we're using an ORM to avoid doing so)
It can be useful for some special complex queries but generally it is not what you want.
Some how modifying the templates used to generate the SQL to add a where clause on each statement.
Too complex and on completely different level of abstraction.
Some how modifying the templates used to generate the LINQ in the controllers (we may use MVC).
Close to ideal solution. You simply need to wrap access to your entity set into some code which will look like:
public class MultiTenantAccess<T> where T : IMultitenant
{
private IDbSet<T> set;
...
public IQueryable<T> GetQuery(int tenantID)
{
return set.Where(e => e.TenantID == tenantID);
}
}
Sometimes this is core for something called Generic repository but it is really just a wrapper around EF set. You will always use GetQuery to query your data store instead of using DbSet directly.
you may also separate the tenants data into different databases
or into same database, but with different schemas? You can read more about this in an old MSDN article called "Multi-Tenant Data Architecture"
I need to access data from pre-existing tables. I've started working my way through creating a module to display the data etc. However, Orchard is prefixing the table commands with the 'Table_Prefix' and 'Module Name'.
Is there any way I can specify what table to bind the model, so that I can use the existing IRepository
I'm trying to steer clear of modifying the core code, or implement my own IRepository ( which I've got a feeling is what I'm going to have to do.)
Thanks in advance.
You can create custom table naming convention (so that it would fit your current naming) by altering the core code, in three ways:
Record name mapping is created in BuildRecord method of
CompositionStrategy class
(Orchard.Framework/Environment/ShellBuilders/CompositionStrategy), so you can simply modify the code here.
By altering the Apply method of Orchard.Data.Conventions.RecordTableNameConvention class. This is where the record table name mappings (built in point 1.) get pushed to NHibernate.
Create your own implementation of FluentNHibernate.Conventions.IClassConvention (similar to RecordTableNameConvention mentioned above and replace the default one used by AutoMap in Orchard.Data.Providers.AbstractDataServicesProvider's CreatePersistenceModel(...) method with it.
You could also create your own IDataServicesProvider implementation, but that would surely be an overkill if you only need to change the table naming convention.
I was modifying CompositionStrategy and discovered that you have to modify the following
1. SetupService.cs (Modules\Orchard.Setup\Services):
Tables hardcoded in the Setup method are
"Orchard_Framework_DataMigrationRecord" and
"Settings_ShellDescriptorRecord"
2. InfosetController.cs (Modules\Upgrade\Controllers):
Multiple tables were hardcoded in this class which need to be updated.
3. DataMigrationManager.cs (Data\Migration):
Replace the SchemaBuilder parameters to the contructor.
I have a problem with the following Linq query using Entity Framework:
from o in ctx.Entity
where o.EntityID = entityid
select o;
Simple enough right? Well the 'Entity' set is the parent class of a whole lot of other classes. The generated SQL for this simple query is about 20K worth of characters with a slew of 'case' and 'union'. In addition of taking a while for the framework to compile the query, it takes a while to execute too.
So how can I improve the SQL generated by the framework in case of queries using classes with heritage? Or what other technique can I use to avoid this problem?
AD
The reason it is doing that is because of the relationships of Entity with other tables in your database. To cut down on that, you need to read up on how to better control the explicit/lazy loading of references that EF is doing for you
http://blogs.msdn.com/jkowalski/archive/2008/05/12/transparent-lazy-loading-for-entity-framework-part-1.aspx
No post like this would be complete without a plug for nhibernate, which is more powerful/robust/performant/and easier to use ;-) but hopefully that link will help you out