Passing variables to sql in a unix shell script

Hi

Hopefully this is the correct area for this question- was not sure if it should come under UNIX or Oracle.

Been struggling all morning with this and wondered if anyone could help.  Basically I'm creating a variable from a sql statement and then passing this variable into another sql statement as a parameter and it does not work.  If I create the variable manually i.e EOD_TYPE="'EOD'" and then pass the parameter to the 2nd sql statement as ${EOD_TYPE} it works, if I use a select to create the variable i get the following error:
SP2-0042: unknown command "'EOD'" - rest of line ignored.

It's quite a short script so I'll paste it below for reference.

thanks in advance

Paul


#!/bin/ksh

#EOD_TYPE="'EOD'"

EOD_TYPE=`sqlplus -s /   <<EOF
set head off
set feedback off
set pages
select decode(to_char(bus_date,'Day'),'Friday','''EOW''','''EOD''') from trading_area where trga_code='EUR';
EOF`

EOD_RUN_TIME=`sqlplus -s /   <<EOF
set head off
set feedback off
set pages
select proc_time_min*60 from eod_run_time where eod_type=${EOD_TYPE};
EOF`

echo $EOD_RUN_TIME