|Related to : outer joins models that are not associations|
|Polymorphic models (not associations!) in Rails|
Yep. Single Table Inheritance.
Add a type:string column to a table for a model you wish to inherit
from, then create new classes that inherit from your base model (say,
Animal). An instance of this class (like, say, Cat) is defined as
Animal, whose type is "Cat".
Another of my answers with an explaination on how to use it
|In sql, can you join to a select statement that references the outer tables in other joins?|
How about a CTE approach:
ROW_NUMBER() OVER (PARTITION BY Id, ORDER BY Primarykey
Desc) AS RN
LEFT JOIN CTE
ON CTE.ID = Y.ID
WHERE CTE.RN = 1
|Sails.js associations: "Many" side of one-to-many associations not saving to MongoDB or Postgres (vs. disk db)|
The .create method doesn't return the populated data in it's callback.
If you query the Feed model and populate the posts association you
should see the data.
|django filtering querysets causes 'AppRegistryNotReady: Models aren't loaded yet.' with forms within models.py|
This seems to be a problem with that library. I suggest implementing
you own logical delete (which is rather easy with a
LogicalDeleteManager and a LogicalDeleteModel) or using a lower
version of django
As a simplistic example:
def __init__(self, show_deleted_objects=False)
|Apply generic class @MappedSuperclass as targetEntity.Error: @ManyToOne on models.Unit.parent references an unknown entity: models.GenericHierarchic|
I know this is a late reply but if a solution is still required here
This issue is because GenericHierarchicalDictionary is an abstract
class. Hibernate does not know what entity type the property
references. Instead what you need to do is use the inheriting class as
the type (in this case Unit).
So the property would be :-
public T parent;