ALMongoDBClient

Delphi Client for MongoDB database.

A Delphi component (with connection pool) to access a mongoDB server. a connection pool is a cache of database connections maintained so that the connections can be reused when future requests to the database are required. In connection pooling, after a connection is created, it is placed in the pool and it is used over again so that a new connection does not have to be established. If all the connections are being used, a new connection is made and is added to the pool. Connection pooling also cuts down on the amount of time a user must wait to establish a connection to the database.

Exemple :

aJSONDoc := TALJSONDocument.create;
aMongoDBClient := TAlMongoDBClient.create;
try
  aMongoDBClient.Connect('', 0);
  aMongoDBClient.SelectData('test.exemple',
                            '{fieldA:123}', // the query
                            '{fieldA:1, fieldB:1}', // the return fields selector
                            aJSONDoc.node);
  aMongoDBClient.disconnect;
  for i := 0 to aJSONDoc.node.childnodes.count - 1 do
    with aJSONDoc.node.childnodes[i] do
      writeln(aJSONDoc.node.childnodes[i].nodename + '=' + aJSONDoc.node.childnodes[i].text)
finally
  aMongoDBClient.free;
  aJSONDoc.free;
end;

Exemple with connection pool :

aMongoDBConnectionPoolClient := TAlMongoDBConnectionPoolClient.create(aDBHost, aDBPort);
try

  ::Thread1::
  aMongoDBConnectionPoolClient.SelectData('test.exemple',
                                          '{fieldA:123}', // query
                                          '{fieldA:1, fieldB:1}', // return fields selector
                                          aLocalVarJSONDOC.node);

  ::Thread2::
  aMongoDBConnectionPoolClient.SelectData('test.exemple',
                                          '{fieldA:999}', // query
                                          '{fieldA:1, fieldB:1}', // return fields selector
                                          aLocalVarJSONDOC.node);

finally
  aMongoDBClient.free;
end;

Exemple tail monitoring :

aMongoDBTailMonitoringThread := TAlMongoDBTailMonitoringThread.Create(
  aDBHost,
  aDBPort,
  'test.cappedCollectionExemple'
  '{}', // the query
  '{fieldA:1, fieldB:1}', // the return fields selector

  Procedure (Sender: TObject; JSONRowData: TALJSONNode)
  begin
    writeln('New item added in cappedCollectionExemple: ' + 
            JSONRowData.childnodes['fieldA'].text);
  end,

  procedure (Sender: TObject; Error: Exception)
  begin
    writeln(Error.message);
  end
);
....
aMongoDBTailMonitoringThread.free;