Can someone please derive a concrete example from the following: http://www.urdalen.com/blog/?p=210 ..that shows how to deal with one-to-many and many-to-many relationships? I've emailed the author some time ago but received no reply. I like his idea, but can't figure out how to implement it beyond simple single table relations. Not...
If the framework is persistence agnostic, can my unit tests construct a file system version of the persistance store underneath my entity model? I'll be using the model first features of entity framework in the GUI for sure because it's too easy for my devs to make schema changes and keep DAL layer in sync. Has anyone tried using the m...
There are a few books about specific ORM products such as Hibernate or Linq to SQL, but I would be quite interested in any material on the more general principles, history etc of ORM. Do you know of any books, white papers, well researched blog posts etc on this topic? Thanks /Erik ...
create table person ( name varchar(15), attr1 varchar(15), attr2 varchar(1), attr3 char(1), attr4 int ) How I can use basic ORM in Perl by taking a simple table like the one above and mapping it to Perl objects? Next I'd like to perform basic operations like select results using some criteria system Perl like synt...
Hello All I am having trouble creating a mapping when the List type is an interface. It looks like I need to create an abstract class and use the discriminator column is this the case? I would rather not have to as the abstract class will just contain an abstract method and I would rather just keep the interface. I have an interface le...
This recent question on doing ORM in Perl proved somewhat timely, as I was just looking at Perl ORMs yesterday. Unfortunately, I was not particularly satisfied with what I found: They all appear (at least in their documentation) to focus primarily on the relational side of the object-relational divide. "Use our ORM to provide an OO(is...
I am messing around with Doctrine (version 1.0.3) to see if would make a good fit for the collection of apps I am writing. I am trying to do a query and return only 3 fields. I am getting the correct fields in one table, but the join table I am getting everything when I only want one field. I have written out the what the SQL should b...
What is the smartest way to get an entity with a field of type List get persisted? Command.java package persistlistofstring; import java.io.Serializable; import java.util.ArrayList; import java.util.List; import javax.persistence.Basic; import javax.persistence.Entity; import javax.persistence.EntityManager; import javax.persistence.G...
I've inherited a rather large application that really could use some cleanup. There is data access code littered throughout the application. In code behinds, some in business logic classes, some inline in in classic asp pages. What I'd like to do is refactor this code, removing all the data access code into a few DAL classes. All the...
I'm doing some research for my end of degree project: a multiplattform application developed using .net3.5 and mono2.0 I need some opinion about what you people think is the best Object Relational Mapping framework which will also run with mono. Additionaly, any opinion about what ORM will work the best for my project, will be handy (...
In an ORM you can have nice syntax like this: my $results = Model.objects.all()[10]; And in the Django ORM it even quite nicely handles foreign key relationships and many to many relationships all through the ORM. However, in MySQL you can run a query like this: SELECT t1.column1 , t2.column2 , t3.column3 FROM db1.table...
Doesn't an ORM usually involve doing something like a select *? If I have a table, MyThing, with column A, B, C, D, etc, then there typically would be an object, MyThing with properties A, B, C, D. It would be evil if that object were incompletely instantiated by a select statement that looked like this, only fetching the A, B, not ...
Hi, I'm playing around at the start of a personal project in C# and MySQL. I am familiar with the use of the Gentle Framework (using MyGeneration to generate the classes, based on the data model). Here's what I like about Gentle; Simple-to-use [class].Retrieve(id) / [object].Persist() semantics with strong-typing of fields; I start...
We are in the process of porting a legacy system to .NET, both to clean up architecture but also to take advantage of lots of new possibilities that just aren't easily done in the legacy system. Note: When reading my post before submitting it I notice that I may have described things a bit too fast in places, ie. glossed over details. I...
This is one is for any of you Doctrine users out there. I have a PHP CLI daemon process that checks a table every n seconds to find entries that haven't been processed. It's basically a FIFO. Anyways, I always exceed the memory allocated to PHP becuase Doctrine does not free it's resources. To combat this problem it provides free for...
Ok well I've been trying to convert my model to use LINQ but didn't want to throw away my current DTO's and their interfaces which are scattered through the domain. I managed to find this blog post which has outlined the process quite nicely: Achieving POCOs in LINQ To SQL I have the managed to get the retrieval of records to objects ...
Anyone knows what is the status of the Linq to NHibernate project? Is it in any kind of "production"? Cannot find the project site (bug reports, feature requests, people etc.), so that I could try to contribute? The latest post I was able to find was about Linq to NHibernate in LinqPad, and some Ayende's posts back from 2007... ...
I have two classes that are associated with a one-to-one mapping: <class name="Employee" table="Employees"> ... <one-to-one name="Address" class="AddressInfo"> ... </class> I would like to use a criteria expression to get only Employees where the the associated Address class is not null, something like this (which I know doesn't...
I am having trouble deleting orphan nodes using JPA with the following mapping @OneToMany (cascade = CascadeType.ALL, fetch = FetchType.EAGER, mappedBy = "owner") private List<Bikes> bikes; I am having the issue of the orphaned roles hanging around the database. I can use the @org.hibernate.annotations.Cascade Hibernate specific tag ...
Let's say I need to implement domain model for StackOverflow. If I am doing ORM, how can I define (and map) property for fetching "last comments" and other "last" things? It looks to me like this should be reflected in the domain model. Sometimes I might need "all comments" though... ...