database-relations

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Doctrine 1.2 ORM inherited class cant acces to its parent relations

having the class A and the class B that inherits from A, and class C to which A has a ratio of 1: M respectively (A, C), when creating an object of the class B and trying to access form $B->C->attribu[详细]

2023-03-06 17:34 分类：问答
How can I expose a Mongoid embedded collection?

I have mongoid setup in my rails3 app, and have created 2 models. One model is user, and the other mod开发者_开发技巧el is article.[详细]

2023-03-03 11:09 分类：问答
Counting how many time a relation is pointing at the same key

SELECT t.tag_name FROM tags t JOIN resource_tags rt ON rt.tag_id = t.tag_id JOIN resource r ON r.resource_id = rt.resource_id[详细]

2023-02-28 10:17 分类：问答
Assistance with Django model relationships

class Pinyin(models.Model): pinyinWord = models.CharField(max_length=200) englishWord = models.CharField(max_length=1000)[详细]

2023-02-25 23:27 分类：问答
Show results of joined tables even if some values don't match

Access Database table contacts -------------- id surname name table relations --------------- contact_id relation_id[详细]

2023-02-24 05:48 分类：问答
How to magically supply Active Record scopes with arguments?

I\'m not sure this is ev开发者_如何学JAVAen possible, but let\'s see if one of you comes up with a solution. This is more or less about code quality in terms of readability and not an actual problem b[详细]

2023-02-23 13:28 分类：问答
How to create nested objects in Rails3 using accepts_nested_attributes_for?

I cannot figure out how I can setup a form that will create a new Study while also creating the related StudySubject and the Facility. The user_id, facility_id and study_subject_id have to be availabl[详细]

2023-02-18 10:44 分类：问答
cakephp two foreign keys in same table

I have a tournament website with CakePHP, where i need开发者_开发知识库s to manage a condition like below details:[详细]

2023-02-16 11:52 分类：问答
How can I make and enforce a generic OneToOne relation in django?

I\'d like the exact same thing as django.contrib.contenttypes.generic.GenericForeignKey, but OneToOne instead of ForeignKey.I thought an easy (albei开发者_C百科t marginally inelegant) workaround was t[详细]

2023-02-08 05:48 分类：问答
Are there any classification algorithms which target data with a one to many (1:n) relationship?

Has there been any research in the field of data-mining regarding classifying data which has a one to many relationship?[详细]

2023-02-06 06:05 分类：问答