It turns out that I am trying to parameterize a querie , apparently it takes the data but returns an erroneous result for example.
Select campo from tabla where nombre ='pepito'
Does not return anything
select campo from tabla where nombre <>'jose'
**pepito**, juan,horacio
returns the distints and the same happens when I put a minor that, or greater than (in case you consult a numeric field)
str = "SELECT TABLA WHERE ? "+ operador +"?";
PreparedStatement prepstm = null;
Connection conn;
conn = DBConnector.getInstance().conect();
prepstm = conn.prepareStatement(str);
prepstm.setString(1, campo);
prepstm.setString(2, valor);
ResultSet rs = prepstm.executeQuery();