table_exists_action=append和table_exists_action=truncate

table_exists_action=append和table_exists_action=truncate

一、环境准备

1.1 192.168.1.22上创建single01.student表

SQL> select * from single01.student;

        ID       NAME
------------    --------------------------------------------------------------------
         1       xiaoming

expdp导出该表

mkdir -p /backup/expdp0522
create or replace directory dir_dump as '/u01/app/oracle/exp';

expdp  \"/ as sysdba\"  directory=dir_dump dumpfile=u_single01_202205_%U.dump parallel=2 logfile=u_single01_202205.log schemas=single01

impdp在192.168.1.67中导入该表

export ORACLE_SID=jdedb1
impdp \"/ as sysdba\" directory=dir_dump dumpfile=u_single01_202205_%U.dump parallel=2 schemas=single01   logfile=u_single01_202205.log

在192.168.1.67目标端上，

SQL> select * from single01.student;
        ID NAME
---------- --------------------
         1 xiaoming

二、验证append参数

1.修改源库数据

SQL> select * from single01.student;

        ID NAME
---------- --------------------
         1 xiaomingming
         2 xiaozhang

2.导出后导入：

impdp \"/ as sysdba\" directory=dir_dump dumpfile=u_student_01modify_202205_%U.dump parallel=2 tables=single01.student  logfile=u_student_01_202205.log table_exists_action=append

在192.168.1.67目标端上，

SQL> select * from single01.student;
        ID NAME
---------- --------------------
         1 xiaoming
         1 xiaomingming
         2 xiaozhang

可以看见，对不impdp之前得数据，参数append不能分辨已有数据，而是直接在后面全表追加

三、验证truncate参数

1.修改源库数据

SQL> update single01.student set name='xiaozhangzhang' where id=2;

1 row updated.

SQL> insert into single01.student values(3,'xiaoli');

1 row created.

SQL> commit;

Commit complete.

SQL> select * from single01.student;

        ID  NAME
---------- ----------------------------------------------------------------------
         1  xiaomingming

         2  xiaozhangzhang

         3  xiaoli

2.导出后导入数据

expdp  \"/ as sysdba\"  directory=dir_dump dumpfile=u_student_02modify_202205_%U.dump parallel=2 logfile=u_student_02modify_202205.log tables=single01.student
impdp \"/ as sysdba\" directory=dir_dump dumpfile=u_student_02modify_202205_01.dump parallel=2 tables=single01.student   logfile=u_student_02_202205.log table_exists_action=truncate

此时在192.168.1.67目标端上检查

SQL> select * from single01.student;

        ID  NAME
---------- ----------------------------------------------------------------------
         1  xiaomingming

         2  xiaozhangzhang

         3  xiaoli

truncate参数是删除目标端67上得原有数据，再将新数据导入