设置变量时如何在Shell脚本中运行SQL命令？我试过这种方法，它不执行命令，它认为命令只是一个字符串。

#!/bin/ksh
variable1=`sqlplus -s username/pw@oracle_instance <<EOF
SET PAGESIZE 0 FEEDBACK OFF VERIFY OFF HEADING OFF ECHO OFF
select count(*) from table;
EXIT;
EOF`
if [ -z "$variable1" ]; then
  echo "No rows returned from database"
  exit 0
else
  echo $variable1
fi