今天登录一台服务器用roote用户登录的,在切换到oracle用户，执行sqlplus sys/ as sysdba进入数据库提示如下错误：

SP2-0750: You may need to set ORACLE_HOME to your Oracle software directory

在/home/oracle目录下查看文件.bash_profile，它是隐藏文件。

$cat.bash_profile
#.bash_profile
#Getthealiasesandfunctions
if[-f~/.bashrc];then
.~/.bashrc
fi
#Userspecificenvironmentandstartupprograms
PATH=$PATH:$HOME/bin
exportPATH
exportORACLE_BASE=/u01/app/oracle
exportORACLE_HOME=/u01/app/oracle/product/11.1.0/db_1
exportORACLE_SID=orcl
exportPATH=$ORACLE_HOME/bin:$PATH
exportLD_LIBRARY_PATH=$ORACLE_HOME/lib
LANG=zh_CN.UTF-8;exportLANG
NLS_LANG='SIMPLIFIEDCHINESE_CHINA.AL32UTF8';exportNLS_LANG

[oracle@localhost ~]$ cd $ORACLE_HOME

-bash: cd: /u01/app/oracle/product/11.1.0/db_1: 没有那个文件或目录

发现oracle安装定义的家目录是在/u01/app/oracle/product/11.1.0/db_1目录下的
u01目录是root用户的权限，在切回到root用户，执行如下命令：
[root@localhost~]#cd$ORACLE_HOME
[root@localhostdbhome_1]#pwd
/u01/app/oracle/product/11.2.0/dbhome_1
[root@localhostdbhome_1]#sqlplus/assysdba
或是
[root@localhostdbhome_1]#cdbin
[root@localhostdbhome_1]#pwd
/u01/app/oracle/product/11.2.0/dbhome_1/bin
[root@localhostbin]#./sqlplus/assysdba
sql*Plus:Release11.2.0.4.0ProductiononThuOct1217:20:482017
Copyright(c)1982,2013,Oracle.Allrightsreserved.
Enterpassword:
Connectedto:
OracleDatabase11gEnterpriseEditionRelease11.2.0.4.0-64bitProduction
WiththePartitioning,OLAP,DataMiningandRealApplicationTestingoptions
sql>

问题解决！