Shell Programming and Scripting

Guys,
My requirement is to spool the resultset of an SQL query to a text file.And one of the select columns of the SQL query is obtained dyamically from the result set of 2 other SQL queries.

And shell scripts looks as below:

OUTPUT=$(sqlplus -s xxxx/yyyy@xyz101 << EOF | grep -v "^$"
set head off
select a.col_name
......................;

select a.col_name
......................;
exit
EOF)

ls_curr_fact=$(echo $OUTPUT | awk '{ print $1 }')
ls_last_fact=$(echo $OUTPUT | awk '{ print $2 }')

ls_fact_amount="sum(${ls_curr_fact}-${ls_last_fact})"

sqlplus -s xxxx/yyyy@xyz101 << EOF | tee -a ${LOG_FILE}

SET SHOWMODE off
SET FEEDBACK OFF
SET VERIFY off
SET RECSEP off
SET TRIMSPOOL on
SET LINESIZE 20000
SET HEADING OFF
SET PAGESIZE 0
SET PAGES 0

WHENEVER SQLERROR EXIT SQL.SQLCODE;

spool ${TEMP1}
SELECT 'B'||','||FD.GEO_ID||','||FD.PROD_ID||','||','||','||','||','||$ls_fact_amount.............

You can see the select column "ls_fact_amount" is obtained from the resultset of two other queries above.
The cumbersome with the above block is that I've two SQL connections to the same database instance.
Could someone suggest changes to my block to simply the SQL connections to just one and get my job done.

Thanks,
Bhagat