Questions tagged [object-persistence]
147 questions
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How to contain an Entity inside another Entity when persisting EMF models, when such a relation is defined in meta-model?
I am trying to create a.XMI file for some Data I got from database, from an already defined metadata. The ecore has defined entities like :
Entity A
|_Entity B
|_Entity C
|_Entity D.
But the model generated for me shows entities like…
EclipseSucks
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1 answer
Implementing Transparent Persistence
Transparent persistence allows you to use regular objects instead of a database. The objects are automatically read from and written to disk. Examples of such systems are Gemstone and Rucksack (for common lisp).
Simplified version of what they do:…
Jules
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6 answers
Save objects to a database?
So far in my .Net coding adventures I've only had a need to save information to files. So I've used XmlSerializer and DataContractSerializer to serialize attributed classes to XML files. My next project, however, requires that I save and retrieve…
Eric Anastas
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What object persister should I use for POJOs?
I know that RoboSpice provides some built-in ObjectPersisters. Can I use one of them or should I write my own to cache lightweight POJOs?
I tried using the built-in ones, but I got an Exception that the class I was trying to cache couldn't be…
Daniel Rusev
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1 answer
JPA: persisting object, parent is ok but child not updated
I have my domain object, Client, I've got a form on my JSP that is pre-populated with its data, I can take in amended values, and persist the object.
Client has an abstract entity called MarketResearch, which is then extended by one of three more…
Jimmy
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JPQL TIMEDIFF equvalent
Is there an equvalent of the SQL TIMEDIFF functionality in JPQL? Is that possible to query with JPQL to find the records in specific time range?
Gennady Shumakher
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6 answers
how to store data in c# application in a portable form?
I'm writing an application using windows form and c# 3.0. I was wondering if there is a recommended way of persist data across time. However, i do not want to touch the machine it is running on, as a result, i would like to store the data in the…
FurtiveFelon
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4 answers
DDD Value Object: How to persist entity objects without tons of SQL joins?
Obviously I am wrong in saying that DDD is similar to EAV/CR in usefulness, but the only difference I see so far is physical tables build for each entity with lots of joins rather than three tables and lots of joins.
This must be due to my lack of…
Zachary Scott
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Properly Implementing a One to Many Unidirectional Relationship in Hibernate
I'm trying to learn how to use Hibernate to implement Java Object Persistence. Specifically, I'm trying to figure out how to implement a unidirectional one to many mapping. I've read the hibernate documentation and the numerous Stackoverflow…
Daniel Bingham
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Is there an NSCoding-like facility in Python?
As an iOS developer recently experimenting with Python, I'm curious to know if there's something like NSCoding that would allow me to implement a method or a pair of methods which would define how my objects can be automatically saved to disk, much…
Moshe
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Using two tables, where does the data retrieval go (First step in MVC)
I am new to MVC proramming (And even object based). So coming from PhP 4.* I moved into OOP, MVC and Cake..
I am building a site which Insitutes from difference COUNTRIES can use to store their data (And more). I am now building the basic…
Jelle Ferwerda
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3 answers
Share objects between tasks in a thread pool but not between threads in Java
I'm trying to create a multithreaded application in Java using ExecutorService thread pools. The application basically queries a third party service for data about a given keyword. Since I have many keywords and each request takes some time to…
Yiling
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GAE datastore will not persist owned 1:1 relationship within embedded JDO class
I have three @PC classes:
@PersistenceCapable
class A {
@PrimaryKey @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
@Extension(vendorName = "datanucleus", key = "gae.encoded-pk", value = "true")
private String id;
…
comeGetSome
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Db4O - Can I save a String?
I have the following code:
Assert.IsTrue(Repository.FindAll().Count() == 0);
string newString = "New String";
Repository.Save(newString);
Assert.IsTrue(Repository.FindAll().Count() == 1);
But it is failing. I suppose it has…
Miguel Ping
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3 answers
Implements save (or commit) and rollback methods to a Map
I'm searching for a fast and convenient way to add save() and rollback() to a standard Map. Let's say i have an object 'table' of class Table which in turn has a private Map called 'rows'. What I'm trying to achieve is a fast and without memory…
Gabriele B
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