function objs = test_high_level_query

% Try to get some data for a particular channel between t1 and t2
%
% M Hewitson


channels = {'channelX', 'channelZ'};
ts       = timespan('2009-01-01 00:00:00', '2009-01-01 00:30:00');

hostname = 'btlab.science.unitn.it';
database_name = 'ltpda_test';


% Make db connection
conn = utils.mysql.connect(hostname, database_name);

objs = hlq(conn, channels, ts);

% Close connection
close(conn);


% A prototype for the kind of high-level query functions we might need
function objsOut = hlq(conn, channels, ts)

objsOut = [];

for j=1:length(channels)

  channel = channels{j};

  q =      ['select objmeta.obj_id from objmeta,ao,tsdata ' ...
            'where objmeta.obj_id=ao.obj_id ' ...
            'and ao.data_id=tsdata.id ' ...
    sprintf('and objmeta.name=''%s''', channel) ...
    sprintf('and tsdata.t0+INTERVAL tsdata.nsecs SECOND  >= ''%s''', char(ts.startT)) ...
    sprintf('and tsdata.t0 <= ''%s''', char(ts.endT))];

  % execute query
  info = utils.mysql.dbquery(conn, q)
  
  % collect objects  
  objs = ltpda_uo.retrieve(conn, [info{:}]);
  
  % join these up
  ojn = join([objs{:}]);
  
  % split out the bit we want
  os = split(ojn, plist('split_type', 'interval', 'timespan', ts));
  
  objsOut = [objsOut os];
  
end

