HowToUseTheRPCDatabaseAPI

RPC database CRUDL interface

Example:

Using CRUDL for "fact" objects

In the API definition, we have:

• This record definition:

   record fact_entry (uri uri, int i, string subject, atom predicate, string object) 

• a module declaration for the "database" module,

• and these call definitions within it:

   method create_fact_entry (fact_entry f) -> (uri u) -- create a new fact entry in database
   method get_fact_entry (uri u) -> (fact_entry f) -- get a specific fact entry from database
   method update_fact_entry (uri u, fact_entry f) -> () -- update a specific fact entry in database
   method delete_fact_entry (uri u) -> () -- delete a specific fact entry from database
   method list_fact_entries () -> (LIST_OF fact_entry f) -- list all fact entries in database

---

So:

given this, the database interface automagically creates database access methods for each of these,

so you can do this:

(in Python, assuming you already have an implementation of the RPC-over-JSON-over-AMQP protocol)

Create a record

headers = {
  'message_type': 'rpc_request',
  'method': 'create_fact_entry'
}
u = json_rpc.call('database', contentType='application/json', headers, {'subject': 's', 'predicate': 'p', 'object': 'o', 'i': 42})

Modify it

headers = {
  'message_type': 'rpc_request',
  'method': 'update_fact_entry'
}
json_rpc.call('database', contentType='application/json', headers, {'u': u, 'changes': {'subject': 's', 'predicate': 'p', 'object': 'o', 'i': 54}})

Access it

headers = {
  'message_type': 'rpc_request',
  'method': 'get_fact_entry'
}
print json_rpc.call('database', contentType='application/json', headers, u)

List all of them, and delete them all

list_headers = {
  'message_type': 'rpc_request',
  'method': 'list_fact_entries'
}
delete_headers = {
  'message_type': 'rpc_request',
  'method': 'delete_fact_entry'
}
for u in json_rpc.call('database', contentType='application/json', list_headers, None):
    json_rpc.call('database', contentType='application/json', delete_headers, u)