orm

Multiple foreign keys to same table using Elixir

Hello, I am new to ORMs in general. I have a table (lets call it Entity) with columns -- ID expression type ( can be 'long_word', 'short_word' or 'sentence' ) Often, the first two types occur in a 'sentence', so, I want to maintain another table which maps 'Sentences' to 'long_word' or 'short_word' using the 'ID' field. All i need...

Kohana ORM syntax question

I'm using the "join_table" function with Kohana's ORM to build a query. The following works: $category = ORM::factory('category')->join_table('product'); But this doesn't: $category = ORM::factory('category'); $category->join_table('product'); The documentation uses the second as an example, but it returns 0 while the first example...

EF4 0..1 relationship leads to Error 2016: Condition cannot be specified

This is very similar to a previous question (and may be the exact same question) but I really didn't understand the answers enough to be able to tell for sure. I am using Entity Framework 4 in Visual Studio RC1 to create an azure service app (so it is .Net 3.5). I have a database with a lot of patterns like the following: Thing ...

Kohana 2.3.4 ORM pivot table query

I'm trying to query a pivot table with Kohana's ORM and I'm wondering if there is a built in function I'm missing. Currently I only have 2 models setup for the tables "categories" and "products". There is a pivot table "categories_products", but I don't need a model for it when inserting data with this: $product = ORM::factory('product'...

Eager/Lazy loaded member always empty with JPA one-to-many relationship

I have two entities, a User and Role with a one-to-many relationship from user to role. Here's what the tables look like: mysql> select * from User; +----+-------+----------+ | id | name | password | +----+-------+----------+ | 1 | admin | admin | +----+-------+----------+ 1 row in set (0.00 sec) mysql> select * from Role; +----+...

Hibernate MappingException

I'm getting this Hibernate error: org.hibernate.MappingException: Could not determine type for: a.b.c.Results$BusinessDate, for columns: [org.hibernate.mapping.Column(businessDate)] The class is below. Does anyone know why I'm getting this error?? @XmlAccessorType(XmlAccessType.FIELD) @XmlType(name = "", propOrder = { "busines...

SQLAlchemy: who is in charge of the "session"? ( and how to unit-test with sessions )

I need some guidance on how to use session objects with SQLAlchemy, and how to organize Unit Tests of my mapped objects. What I would like to able to do is something like this: thing = BigThing() # mapped object child = thing.new_child() # create and return a related object thing.save() # will also save the child object In order to a...

Sortable behavior for Doctrine ORM

Does anyone know of an existing implementation of a sortable behavior for Doctrine? I'm actually amazed is isn't in the default behaviors since it's such a common thing in most webapplications. ...

Ternary (and n-ary) relationships in Hibernate

Q 1) How can we model a ternary relationship using Hibernate? For example, how can we model the ternary relationship presented here using Hibernate (or JPA)? NOTE: I know that JPA 2 has added some constructs for building ternary relationships using maps. However, this question assumes JPA 1 or Hibernate 3.3.x and I don't like to use map...

Deleting entity with child relationships using .Net Entity Framework problem

My God, EF is so frustrating. I can't seem to be able to get my head around what I need to do so I can delete an object. I seem to be able to remove the object but not the related child objects. Can anyone tell me what is the rule of thumb when you want to delete all related child objects of a given object? I've tried loading all relat...

DataObjects.NET: a good (flawless, documented, support) ORM?

I am looking for ORM frameworks, came along to NHibernate, Genome, L2S, Entity Framework and now the DataObjects.NET.. So far a I read the documentation it seems pretty cabable, but have you ever tried this ORM? Any issues/bugs with DO.NET would be approciated :) ...

Delete element from Set

Hi. I have 2 classes Tema(Homework) and Disciplina (course), where a Course has a Set of homeworks. In Hibernate i have mapped this to a one-to-many associations like this: <class name="model.Disciplina" table="devgar_scoala.discipline" > <id name="id" > <generator class="increment"/> </id> <set name="listaTeme" table="devgar_sc...

Hibernates generates VARBINARY column with JPA @Enumerated annotation

Hibernates is generating a VARBINARY column with JPA @Enumerated annotation. I'm using SQL Server 2005 w/ JTDS driver. The mapping is dirt simple: @Basic @Enumerated(EnumType.ORDINAL) private MyEnum foo; I would have expected Hibernate to generate an integer column? I've also tried EnumType.STRING (expecting a varchar column) with no ...

SqlCommandBuilder.DeriveParameters(command) and IsNullable

I have written an O/R database wrapper that generates some wrapper methods for stored procs it reads from the database. Now I need to produce some custom wrapper code if an input parameter of a stored proc is defaulted to NULL. The problem is - I get stored proc parameters using: SqlCommandBuilder.DeriveParameters(command) and it do...

ORM market analysis

I would like to see your experience with popular ORM tools outhere, like NHibernate, LLBLGen, EF, S2Q, Genom-e, LightSpeed, DataObjects.NET, OpenAccess, ... From my exp: - Genom-e is quiet capable of Linq & performance, dev support - EF lacks on some key features like lazy loading, Poco support, pers.ignorance... but in 4.o it may ha...

Starter question of declarative style SQLAlchemy relation()

I am quite new to SQLAlchemy, or even database programming, maybe my question is too simple. Now I have two class/table: class User(Base): __tablename__ = 'users' id = Column(Integer, primary_key=True) name = Column(String(40)) ... class Computer(Base): __tablename__ = 'comps' id = Column(Integer, primary_key=Tr...

Doctrine Problem: Couldn't get last insert identifier.

When i try to save data to my model Doctrine throws this exception: Message: Couldn't get last insert identifier. My table setup code is: $this->hasColumn('id', 'integer', 4, array( 'type' => 'integer', 'length' => 4, 'fixed' => false, 'unsigned' => false, 'primary' => true, 'aut...

Decouple a JPA entities jar from persistence.xml in SE environment

Is there a way to reuse a jar with JPA annotated entities in more than one SE applications (as a dependency)? <jar-file> in persistence.xml is not supported in SE environments so is there another way? ...

what is best flexibility and why? Using db views, db tables, stored proc. and objects in tables...

Hi! I want to know what is best practice for using db views, db tables, stored proc. and objects in tables... Which of these is more flexible and why, can You explain? Best regards! ...

Are ORM's counterproductive to OO design?

In OOD, design of an object is said to be characterized by its identity and behavior. Having used ORM's in the past, the primary purpose, in my opinion, revolves around the ability to store/retrieve data. That is to say, ORM objects are not design by behavior, but rather data (i.e. database tables). Case and point: Many ORM tools com...