The principle behind the CQS architectural pattern is that you separate your queries and commands into distinct paths. Ideally, your persistence store can be read/write partitioned, but in my case, there is a single, normalized database. If you are using an ORM (NHibernate in my case), it's clear that the ORM is used when issuing comma...
nHibernate has a great feature called filters, so i can create criterias globally for my applications. I'm starting a project in PHP and i need to use an ORM, i'd like to know if Doctrine has a similar feature to manage query conditions. thanks ...
Say if I have a large dataset, the table has well over a million records and the database is normalized so theres foreign keys and stuff. Ive set up the relations properly and i get a list of the first object applications = EntityLoad("entityName") but because of the relations and stuff the page takes like 24 seconds to load, even when ...
In his book "Patterns of Enterprise Application Architecture", Martin Fowler talks about persistence patterns which are commonly found in software development and particularly in relation to ORMs. Is there a pattern that Hibernate adheres to most closely? ...
I'd like to use the Python version of App Engine but rather than write my code specifically for the Google Data Store, I'd like to create my models with a generic Python ORM that could be attached to Big Table, or, if I prefer, a regular database at some later time. Is there any Python ORM such as SQLAlchemy that would allow this? ...
I am currently working on a Wikipedia API which means that we have a database for each language we want to use. The structure of each database is identical, they only differ in their language. The only place where this information is stored is in the name of the database. When starting with one language the straight forward approach to ...
need to use a good PHP ORM that has elements of Datamapper and i am not clever enough to code it myself. chosen doctrine, but after reading through the user guide, cannot find anything that says how to use identity map to lower calls to database. please show me how to have identity map in doctrine ORM? just read and understood stuff ...
If the application asks for a similar result set to one that has recently been requested, how might the ORM keep track of which results are stale and which can be reused from before without using too many resources (memory) or creating too much architectural complexity? ...
According to the Wikipedia article object relational mapping: is a programming technique for converting data between incompatible type systems in relational databases and object-oriented programming languages I thought an ORM also took care of tranferring the data between the application and the database. Is that not necess...
I was reading about ORMs and one of the descriptions I read said that the ORM interacts with database metadata. Why is this important or relevant? Metadata, as I understand, is just a way of describing what the database contains. So, for example, the database might have an internal table that lists what user tables have been created....
I'd prefer a commercial solution. So not NHibernate. Now i'm playing with LLBLGen pro and i like it but it doesn't seem be DDD friendly. ...
Hi, I'm having one self-referencing class. A child has a reference to its parent and a parent has a list of children. Since the list of children is ordered, I'm trying to map the relation using NHibernate's . This is my mapping: <class name="MyClass"> <id name="Id"> <generator class="native"/> </id> <list name="Children" cas...
Hi, i am having a problem in Fluent NHibernate example utilizing the Many-to-Many relationships, i tried to find out examples on a similar case, and i found tons , but still having the same problem. when run the test project the following exception is thrown: NHibernate.PropertyAccessException: Exception occurred getter of project.Enti...
I am using SqlAlchemy, a python ORM library. And I used to access database directly from business layer directly by calling SqlAlchemy API. But then I found that would cause too much time to run all my test cases and now I think maybe I should create a DB access layer, so I can use mock objects during test instead of access database di...
If I have this in a migration: t.text :body How much text can I fit in :body? (I'm using PostgreSQL if that's relevant) ...
I've been trying to modify the AuditTrail code so that it does not copy ForeignKey fields, but rather copies the related field (ie I don't want a foreign key on my database table for the audit model). I've written a copy_field function that looks like so: def copy_field(field): while(isinstance(field, models.OneToOneField, models.F...
We are making a synchronization between one master database and many slave databases over tight link (7kb). To minimize amount of data send we tag each record that was sent successfully. To do so we created following models: class SynchronizationTag(models.Model): STATUSES = ((0, "Invalid"), (1, "Pending"), ...
I currently have two entities in LLBLGen and would like to merge them together to output to a table to be used in a DevExpress GridControl in the same way that 2 tables joined together with an inner join. Does anyone know how to do this with LLBLGen? ...
What is the simplest ORM implementation around for PHP? I'm looking for something really simple and light (in terms of LOC, since speed it's not crucial I don't need caches and what not), preferably a single file or class package that doesn't depends on XML or other configuration files and it's easy to deploy. Reading other similar ques...
Bill Karwin has a blog post called "Why Should You Use An ORM?" which is being discussed on Reddit and I was confused about a couple of points. In it he says in the comments section: OODBMS and ORM works only on objects that we've instantiated in the application layer. I.e. there's no way to do a query like this: UPDATE B...