Below is the approach to insert query using PostreSQL for Android

    PreparedStatement st=conn.prepareStatement(”INSERT INTO films (title) ”+”VALUES(?) ;”);
    st.setString(1,”On Stranger Tides”);
    int rows=st.executeUpdate();
    st.close();

Go through this 
    https://www.pgcon.org/2011/schedule/attachments/194_pgcon2011-pgdroid.pdf
for more details.