Hello,
a few months ago a wrote about creating alternative approach for using Apache
Cayenne. Actualy I use Cayenne with Click Framework and following scenario came
from practice on several projects. The main idea is to use Cayenne as very
stable background(engine) but alter API to something closer to ActiveRecord like
approach. The result is CayenneObjectManager that implements alternative API
that, as result, generates standard Cayenne queries.
CayenneObjectManager API assumes Java5 as generics are used extensively and is
tested with latest Apache Cayenne M3. Entire package is rather small and is
intended to be extended by other methods. I'm not very experienced JAVA
developer so one thing I would like to ask is, if someone can review the concept
and correct some potencial mistakes or contribute with some ideas etc. I'm open
for correction.
Thanks,
David
See attached file with source at https://issues.apache.org/cayenne/browse/CAY-988
For quick example just image you have a simple table with Role names and imagine
how simply you can work with this:
// Load role object by its name
COManager manager=new COManagerImpl();
// init is based on usage scenario. This can be used in standalone app. for e.g.
web app usage, the context is inititalized automaticly from
DataContext.getThreadDataContext();
co_manager.setContext(DataContext.createDataContext());
Role
role_admin=co_manager.find(Role.class).byProperty("name").EQUALS("admin").first();
// all roles from allowed list as key-pair for checkbox field
Map<String,String>
roles=co_manager.find(Role.class).byProperty(Role.NAME_PROPERTY).IN(allowed_roles).to_pairs("name",
"id");
CayenneObjectsManager - alternative API for working with Apache Cayenne subsystem
// Available use cases
// find one item by ID
co_manager.find(Class).byId(id)
// find all items by property and given condition
co_manager.find(Class).byProperty("property").EQUALS(value)
// find first item by property and given condition
co_manager.find(Class).byProperty("property").BETWEEN(value1,value2).first()
co_manager.find(Class).byProperty("property").LIKE(value).first()
co_manager.find(Class).byProperty("property").IN(range).first()
// find all items
co_manager.find(Class).all()
// find all items by based on CayenneObjectsQuery
co_manager.find(Class).allByQuery(COQuery query)
// find all firts item by based on CayenneObjectsQuery
co_manager.find(Class).allByQuery(COQuery query).firts()
//find all selected items as key-pairs available e.g. for checkbox field
co_manager.find(Class).byProperty("property").EQUAL(value1).to_pairs(key,value)
// aggregate functions
co_manager.aggregate(Class).count("property")
co_manager.aggregate(Class).count("property", COQuery query)
co_manager.aggregate(Class).sum("property")
co_manager.aggregate(Class).sum("property", COQuery query)
co_manager.aggregate(Class).avg("property")
co_manager.aggregate(Class).avg("property", COQuery query)
co_manager.aggregate(Class).count("property",
Query.where("year>$year").addParam("year", 2003));
// common actions
co_manager.create(Class)
co_manager.save()
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