[20211123]sqlplus @与@@的区别.txt

[20211123]sqlplus @与@@的区别.txt --//调式sql脚本，遇到一个古老的问题，就是@与@@的区别的区别。 1.环境： SCOTT@book> @ ver BANNER -------------------------------------------------------------------------------- Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production SCOTT@book> help @  @ ("at" sign)  -------------  Runs the SQL*Plus statements in the specified script. The script can be  called from the local file system or a web server.  @ {url|file_name[.ext]} [arg ...]  where url supports HTTP and FTP protocols in the form:     http://host.domain/script.sql  @@ (double "at" sign)  ---------------------  Runs the specified script. This command is almost identical to  the @ command. It is useful for running nested scripts because it  has the additional functionality of looking for the nested script  in the same url or path as the calling script.  @@ {url|file_name[.ext]} [arg ...] --//@@ 不同在与because it  has the additional functionality of looking for the nested script in the same url or path as --//the calling script. --//我的理解调用脚本的在相同的url或者path指向的脚本。 2.我遇到的问题： $ echo $SQLPATH /home/oracle/sqllaji:/home/oracle/sqllaji/tpt --//我的环境定义了两个PATH.优先查找我写的路径。 $ cat ~/sqllaji/tpt/ev.sql -- Copyright 2018 Tanel Poder. All rights reserved. More info at http://tanelpoder.com -- Licensed under the Apache License, Version 2.0. See LICENSE.txt for terms & conditions. @oerr &1 prompt alter session set events '&1 trace name context forever, level &2';; alter session set events '&1 trace name context forever, level &2'; --//执行遇到的情况如下： SCOTT@book> show verify verify OFF SCOTT@book> @ ev 10046 12 Error 10046 is : ORA-10046: enable SQL statement timing Enter value for 1: 10046 alter session set events '10046 trace name context forever, level 12'; Enter value for 1: 10046 Session altered. --//我开始有点不理解为什么每次必须输入参数1，而参数2不需要输入。 $ cat ~/sqllaji/tpt/oerr.sql -- Copyright 2018 Tanel Poder. All rights reserved. More info at http://tanelpoder.com -- Licensed under the Apache License, Version 2.0. See LICENSE.txt for terms & conditions. -- OERR functionality - list description for and ORA- error code -- The data comes from $ORACLE_HOME/rdbms/mesg/oraus.msb file -- which is a binary compiled version of $ORACLE_HOME/rdbms/mesg/oraus.msg file @@saveset set serverout on size 1000000 feedback off prompt exec dbms_output.put_line(sqlerrm(-&1)) prompt @@loadset --//注解oerr那行正常，原来在sqllaji目录下也有一个oerr.sql. --//两者写法有一点点不同。  $ cat ~/sqllaji/oerr.sql prompt SET serveroutput ON SIZE 1000000 SET feedback off EXEC dbms_output.put_line('Error ' || &&1 || ' is : ' ||sqlerrm(-1 * &&1)); prompt undefine 1 SET feedback ON --//加入路径执行才发现，才发现两者的输出有点点不同。 SCOTT@book> @ oerr 10046 Error 10046 is : ORA-10046: enable SQL statement timing ~~~~~~~~~~~~~~ SCOTT@book> @ tpt/oerr 10046 ORA-10046: enable SQL statement timing --//我做了几个测试。 --// 改名~/sqllaji/oerr.sql => ~/sqllaji/oerr.xxx.测试正常，修改回来。 --// 改名~/sqllaji/tpt/oerr.sql => ~/sqllaji/tpt/oerr.xxx. 测试时必须输入参数1。 --//先临时修改如下： $ cat ev.sql -- Copyright 2018 Tanel Poder. All rights reserved. More info at http://tanelpoder.com -- Licensed under the Apache License, Version 2.0. See LICENSE.txt for terms & conditions. @@oerr &1 prompt alter session set events '&1 trace name context forever, level &2';; alter session set events '&1 trace name context forever, level &2'; --//继续测试： SCOTT@book> @ ev 10046 12 SP2-0310: unable to open file "/home/oracle/sqllaji/tpt/oerr.sql" alter session set events '10046 trace name context forever, level 12'; Session altered. --//也就是打入@@oerr.sql 只能在相同目录下查询并执行。 --//改名~/sqllaji/tpt/oerr.xxx => ~/sqllaji/tpt/oerr.sql。 --//再测试正常。 SCOTT@book> @ ev 10046 12 ORA-10046: enable SQL statement timing alter session set events '10046 trace name context forever, level 12'; Session altered. --//当前正在整理自己以前写的脚本，管理有点乱。