A kind of Query Neighbour algorithm is implemented. But I do not know
the connection information nor the database structure and thu I need the
below help. Also I think it may be better for someone at school to run
it as it will be quite some network delay for me in mainland I think.

Please help me to complete the sql queries (You can search for "query"
to find where I need you) in QueryNeighbour.java as well as the
connection information in DatabaseConnector.java. I or someone at school
can test it then.

I will go on to 1NN after the first method is tested ok.

Signed-off-by: Gary Zhang <gary1412zhang@gmail.com>