Last try to get an answer on this. I have a simple ASP.NET app which uses Hibernate for data access. GUI can call methods on Customer object like "CalculateTotalSumOfOrders()". Lazy loading (even though it's not optimal) will work for me, and when Orders and OrderLines collections are referenced in the domain objects, they will get auto...
I'm running the following code that errors when I try to commit my changes using Cayenne as my ORM. The code is pasted below and errors out on the context.commitChanges();line. The output messages are pasted below the code. Any help on figuring this out would be appreciated. import org.apache.cayenne.access.DataContext; import java...
If I have an existing database, I want to be able to automatically code generate the corresponding Castle ActiveRecord C# classes based on the db schema. My primary intent is to avoid manually creating each class. What are my options for code gen tools with templates that can already specifically do this for Castle ActiveRecord? (Note:...
I have a just one table mapped in a datacontext. Here's the property and attribute on the column of interest: [Column(Storage="_CustomerNumber", DbType="VarChar(25)")] public string CustomerNumber { This column is, in fact, a varchar(25) and has an index. I've got some simple code: DataClasses1DataContext myDC = new DataClasses1Dat...
Is there any Database Abstraction Layer (DAL) or Object Relational Mapper (ORM) that works on Google App Engine (GAE), and on normal relational databases (RDBS), other than web2py's? If not, is anybody working on porting one of the existing DAL/ORM to GAE? ...
Martin Fowler defines an elegant object model for the scheduling of recurring tasks here, which maps to OO code very nicely. Mapping this to a relational database schema for persistence, however, is tricky. Can anyone suggest a schema + SQL combination that encapsulates all the functionality he describes, particularly in the image on p...
I'm pretty sure that I'm not understanding something about JPA (I'm using OpenJPA) and it's causing this problem. I want to make a copy of a Job entity. @Entity @Table(name="Job") public class Job implements Serializable { @Id @GeneratedValue(strategy=GenerationType.IDENTITY) private int id; @ManyToOne private Job ...
I'm trying to map a joined-subclass scenario using Fluent NHibernate. I have a class Entity defined in the namespace Core, and a class SubClass : Entity in the namespace SomeModule Now I obviously don't want class Entity to know about its derived types, the SomeModules namespace references Core - not the other way around. All the examp...
I am using C# 3.0 / .NET 3.5 and planning to build an eCommerce website. I've seen NHibernate, LLBLGEN, Genome, Linq to SQL, Entity Framework, SubSonic, etc. I don't want to code everything by hand. If there is some specific bottleneck I'll manage to optimize the database/code. Which ORM would be best? There is so much available those...
One of my API calls can result in updates to a large number of objects (Django models). I'm running into performance issues with this since I'm updating each item individually, saving, and moving on to the next: for item in Something.objects.filter(x='y'): item.a="something" item.save() Sometimes my filter criterion looks like...
Is there a way to query or just access newly added object (using ObjectContext.AddObject method) in Entity Framework? I mean situation when it is not yet saved to data store using SaveChanges I understand that queries are translated to underlying SQL and executed against data store, and it don't have this new object yet. But anyway, I'm...
EF has been out for awhile now and I'm considering evaluating it - what have your experiences been? I am interested in both web and desktop applications, and maybe some comparisons between EF and other ORM tools that you've used. Learning curve is a factor since there is a team involved. Is this thing a bloated mess, or it is lean and...
Are there any books on the subject that anyone recommends? Where do I learn the key concepts and patterns for ORM in general as it relates to NHibernate specifically? ...
This question is about "best use" scenarios in projects with ORMs like NHibernate, Subsonic, Linq2SQL, etc... All of these tools generate basic entity classes, some with attributes, others without. Do people use these classes as their business classes? Or is there wholesale copying of data from ORM generated classes to manually create...
I am looking for some guideline for my new application while choosing ORM. I want to evaluate EF over NHibernate and LINQ to SQL. I need some expert voice from this wonderful community. You can evaluate on following point. Scalability Learning curve Easy to use Performance ETC. ...
For a number of years I've used Object Role Modeling to design and validate my database schema designs. (The appurtenant software products have been variously named Visiomodeler, Infomodeler, Visual Studio Enterprise Architect ORM Studio, etc.) It's the only truly conceptual database modeling tool I've ever found to be at all useful; in...
I'm trying to generate my models from a schema.xml file on OSX 10.5 with the latest versions of PHP & Propel 1.3 & Phing. All the model classes actually get created, then it just dies, right at the last step. I have already tried chmod -R 777 ./application/config but that didn't help. I have also tried both propel-gen ./ reve...
I come from a java background. But I would like a cross-platform perspective on what is considered best practice for persisting objects. The way I see it, there are 3 camps: ORM camp direct query camp e.g. JDBC/DAO, iBatis LINQ camp Do people still handcode queries (bypassing ORM) ? Why, considering the options available via JPA, D...
I’m looking for a Perl ORM library that has support for reverse engineering of the database schema. All I’ve found so far is http://perlorm.sourceforge.net/ and it appears to have no reverse engineering support. ...
I use SQLAlchemy at work and it does the job really fine. Now I am thinking about best practices. For now, I create a module holding all the SQLA stuff : my_model |__ __init__.py |__ _config.py <<<<< contains LOGIN, HOST, and a MetaData instance |__ table1.py <<<<< contains the class, the model and the mappe...