Customize sqlprompt after sqlplus Logon

Custom sqlplus sqlprompt after logon creates a login under any directory. SQL example: www.2cto.com E: \ oracle-study input content: define _ editor = sublime_textset serveroutput on size 1000000 set trimspool onset long 5000 set linesize 100 set pagesize 9999 column partition format a80 set time on set termout off column propmt_q new_value propmt_qselect upper (user) | '@' | instance_name | '(' | host_name | ')' as propmt_q from v $ instance; set sqlprompt '& propmt_q>' create an environment variable after saving: SQLPATH = E: \ oracle-study and then fail to log on Via sqlplus: ora-12560 google: add another environment variable: ORACLE_SID = ORCL log on again: the effect is D: \ app \ wujiahua \ product \ 11.2.0 \ dbhome_1 \ RDBMS \ ADMIN> sqlplus SQL * Plus: release 11.2.0.1.0 Production on Wednesday January 16 22:22:21 2013 Copyright (c) 1982,201 0, Oracle. all rights reserved. enter User name: system Enter Password: www.2cto.com connect to: Oracle Database 11g Enterprise Edition Release 11.2.0.1.0-ProductionWith the Partitioning, OLAP, Data Mining and Real Application Testing options marked in red to indicate that the customization was successful.