建立一个简单的测试环境：

SQL> CREATE TABLE T1  
  2  (ID NUMBER, NAME VARCHAR2(30));

Table created.

SQL> INSERT INTO T1
  2  SELECT ROWNUM, TNAME       
  3  FROM TAB;

66 rows created.

SQL> CREATE TABLE T2
  2  (ID NUMBER, NAME VARCHAR2(30));

Table created.

SQL> INSERT INTO T2 
  2  VALUES (1, 'A');

1 row created.

SQL> INSERT INTO T2  
  2  VALUES (2, 'B');

1 row created.

SQL> COMMIT;

Commit complete.

如果要导出T1和T2的查询结果，且满足两个条件，就可以考虑使用数据泵的QUERY功能。

第一个条件是查询的全部字段都来自同一张表；

第二个条件是其他表关联当前表字段是唯一的，换句话说，就是当前表和其他表关联后不会产生重复的记录。

SQL> SELECT T1.* FROM T1, T2
  2  WHERE T1.ID = T2.ID;

        ID NAME
---------- ------------------------------
         1 CP_TEST_T
         2 CELL

比如上述的查询结果就可以通过数据泵的QUERY参数来实现，首先对查询变形，变成IN或EXISTS的形式：

SQL> SELECT * FROM T1
  2  WHERE ID IN
  3  (SELECT T2.ID FROM T2 WHERE T2.ID = T1.ID);

        ID NAME
---------- ------------------------------
         1 CP_TEST_T
         2 CELL

下面就可以进行导出了：

[oracle@yans1 ~]$ expdp test/test dumpfile=d_output:t1.dp tables=t1 query='T1:"WHERE ID IN (SELECT ID FROM T2 WHERE T2.ID = ID)"'

Export: Release 10.2.0.3.0 - 64bit Production on 星期日, 13 6月, 2010 19:52:28

Copyright (c) 2003, 2005, Oracle.  All rights reserved.

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - 64bit Production
With the Partitioning, OLAP and Data Mining options
Starting "TEST"."SYS_EXPORT_TABLE_01":  test/******** dumpfile=d_output:t1.dp tables=t1 query=T1:"WHERE ID IN (SELECT ID FROM T2 WHERE T2.ID = ID)"
Estimate in progress using BLOCKS method...
Processing object type TABLE_EXPORT/TABLE/TABLE_DATA
Total estimation using BLOCKS method: 128 KB
Processing object type TABLE_EXPORT/TABLE/TABLE
. . exported "TEST"."T1"                                 5.234 KB       2 rows
Master table "TEST"."SYS_EXPORT_TABLE_01" successfully loaded/unloaded
******************************************************************************
Dump file set for TEST.SYS_EXPORT_TABLE_01 is:
  /home/oracle/t1.dp
Job "TEST"."SYS_EXPORT_TABLE_01" successfully completed at 19:52:32

这种方法比较简单，但是最大的缺点就是限制条件太严格，尤其是所有字段完全来自都一张表，大多数情况都无法满足这个条件。