Connect to sqlplus in a shell script and run SQL scripts

For example:

sqlplus -s admin/password << EOF
whenever sqlerror exit sql.sqlcode;
set echo off 
set heading off

@pl_script_1.sql
@pl_script_2.sql

exit;
EOF

Wouldn't something akin to this be better, security-wise?:

sqlplus -s /nolog << EOF
CONNECT admin/password;

whenever sqlerror exit sql.sqlcode;
set echo off 
set heading off

@pl_script_1.sql
@pl_script_2.sql

exit;
EOF 

If you want to redirect the output to a log file to look for errors or something. You can do something like this.

sqlplus -s <<EOF>> LOG_FILE_NAME user/passwd@host/db
#Your SQL code
EOF

This should handle issue:

1. WHENEVER SQLERROR EXIT SQL.SQLCODE
2. SPOOL ${SPOOL_FILE}
3. $RC returns oracle's exit code
4. cat from $SPOOL_FILE explains error

SPOOL_FILE=${LOG_DIR}/${LOG_FILE_NAME}.spool 

SQLPLUS_OUTPUT=`sqlplus -s  "$SFDC_WE_CORE" <<EOF 
        SET HEAD OFF
        SET AUTOPRINT OFF
        SET TERMOUT OFF
        SET SERVEROUTPUT ON

        SPOOL  ${SPOOL_FILE} 

        WHENEVER SQLERROR EXIT SQL.SQLCODE
        DECLARE 

        BEGIN
           foooo 
        --rollback; 
        END;
    /
    EOF` 

RC=$?

if [[ $RC != 0 ]] ; then

    echo " RDBMS exit code : $RC  "     | tee -a ${LOG_FILE}
    cat ${SPOOL_FILE}                   | tee -a ${LOG_FILE}

    cat ${LOG_FILE} | mail -s "Script ${INIT_EXE} failed on $SFDC_ENV" $SUPPORT_LIST

    exit 3

fi

Some of the other answers here inspired me to write a script for automating the mixed sequential execution of SQL tasks using SQLPLUS along with shell commands for a project, a process that was previously manually done. Maybe this (highly sanitized) example will be useful to someone else:

#!/bin/bash
acreds="user_a/supergreatpassword"
bcreds="user_b/anothergreatpassword"
hoststring='fancyoraclehoststring'

runsql () {
  # param 1 is $1
sqlplus -S /nolog << EOF
CONNECT $1@$hoststring;
whenever sqlerror exit sql.sqlcode;
set echo off
set heading off
$2
exit;
EOF
}

echo "TS::$(date): Starting SCHEM_A.PROC_YOU_NEED()..."
runsql "$acreds" "execute SCHEM_A.PROC_YOU_NEED();"

echo "TS::$(date): Starting superusefuljob..."
/var/scripts/superusefuljob.sh

echo "TS::$(date): Starting SCHEM_B.SECRET_B_PROC()..."
runsql "$bcreds" "execute SCHEM_B.SECRET_B_PROC();"

echo "TS::$(date): DONE"

runsql allows you to pass a credential string as the first argument, and any SQL you need as the second argument. The variables containing the credentials are included for illustration, but for security I actually source them from another file. If you wanted to handle multiple database connections, you could easily modify the function to accept the hoststring as an additional parameter.