更新uid为1002的记录的位置信息：

public class UpdateJDBC {
    public static void main(String args[]) {
        Connection conn = null;
        Statement stmt = null;
        try{
            Class.forName("org.postgresql.Driver");
            conn = DriverManager.getConnection("jdbc:postgresql://139.224.168.86:5432/doc","citybrain", "Tsdb2gaia");
            conn.setAutoCommit(false);
            stmt = conn.createStatement();
            String sql = "UPDATE tsdb_test set position = ST_MakePoint(12.1,23.2) WHERE uid=1002;";
            stmt.executeUpdate(sql);
            conn.commit();
            // 数据库默认是1s刷新
            Thread.sleep(2000);
            ResultSet rs = stmt.executeQuery( "SELECT uid, time, ST_AsText(position) AS pos FROM tsdb_test;" );
            while ( rs.next() ) {
                long id = rs.getLong("uid");
                String  time = rs.getString("time");
                String position  = rs.getString("pos");
                System.out.println( "uid = " + id + ", time = " + time + ", position = " + position );
                System.out.println();
            }
            rs.close();
            stmt.close();
            conn.commit();
            conn.close();
        } catch (Exception e) {
            System.err.println(e.getClass().getName() + " : " + e.getMessage());
            System.exit(0);
        }
        System.out.println("update successfully");
    }
}