select * from nls_database_parameters t where t.parameter='NLS_CHARACTERSET';
select * from v$nls_parameters where parameter='NLS_CHARACTERSET';

vi /home/oracle/dbbak/shell/dbbak.sh

#[plain]view plaincopy
#!/bin/sh
export ORACLE_BASE=/u01/app/oracle
export ORACLE_HOME=$ORACLE_BASE/product/11.2.0/dbhome_1
export ORACLE_SID=orcl
export PATH=$PATH:$HOME/bin:$ORACLE_HOME/bin
export DATA_DIR=/home/oracle/dbbak/data
export LOGS_DIR=/home/oracle/dbbak/log
export DELTIME=`date -d "30 days ago" +%Y%m%d`
export BAKUPTIME=`date +%Y%m%d%H%M%S`
export NLS_LANG=AMERICAN_AMERICA.AL32UTF8
mkdir -p $DATA_DIR
mkdir -p $LOGS_DIR
echo "Starting bakup..."
echo "Bakup filepath$DATA_DIR/$BAKUPTIME.dmp"
exp user/pwd@orcl file=$DATA_DIR/orcl$BAKUPTIME.dmp log=$LOGS_DIR/orcl$BAKUPTIME.log
echo "Delete the file bakup before 30days...filepath: $DATA_DIR/orcl$DELTIME*.dmp "
rm -rf $DATA_DIR/orcl$DELTIME*.dmp
rm -rf $LOGS_DIR/orcl$DELTIME*.log
echo "Delete the file bakup successfully."
echo "Bakup completed."

export DELTIME=`date -d "30 days ago" +%Y%m%d` 配置保留数据的时间，这里是保留30天，根据自己需要和服务器的存储空间进行相应的修改即可；
export NLS_LANG=AMERICAN_AMERICA.AL32UTF8 字符编码格式，需跟第一步查询中结果保持一致；
exp DISPLAY/DISPLAY@orcl file=$DATA_DIR/orcl$BAKUPTIME.dmp log=$LOGS_DIR/orcl$BAKUPTIME.log

sqlplus user/pwd  // 用户名密码登录数据库
SQL> SELECT 'drop table ' || table_name || ';' FROM USER_TABLES ORDER BY TABLE_NAME;

    export NLS_LANG=AMERICAN_AMERICA.AL32UTF8;
导入数据：
imp DISPLAY/DISPLAY file=/home/oracle/dbbak/data/orcl20191121113703.dmp fromuser=DISPLAY touser=DISPLAY ignore=y;
// ignore=y 忽略错误，继续执行