Thanks Stephen.
What I have done to get around this is:
In the select I get all columns i.e. * from the main table, and I select the column I want from another table and the alias name for this column is same as the column name I want to exclude.
When I execute the query in the database it gives me both the columns in the data output; but with
JDBC while retrieving the values, when I invoke getString("<alias_name>") it gives me the value of the column from the second table. Thats what I need so my problem gets solved.