$ sqlplus "/as sysdba"
SQL*Plus: Release 10.2.0.1.0 - Production on 星期一 10月 9 14:45:19 2006
Copyright (c) 1982, 2005, Oracle. All rights reserved.
连接到:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
SQL>
SQL> select * from exitgogo8;
TEST
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1
2
3
TEST
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4
SQL> select * from exitgogo8 where rownum=1;
TEST
--------------------------------------------------------------------------------
1
SQL> select * from exitgogo8 where rownum=2;
未选定行
SQL> select * from exitgogo8 where rownum=3;
未选定行
SQL> select * from exitgogo8 where rownum>1;
未选定行
SQL> select * from exitgogo8 where rownum>2;
未选定行
SQL> select * from exitgogo8 where rownum>-1;
TEST
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1
2
3
TEST
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4
SQL> select * from exitgogo8 where rownum>0;
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TEST
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1
2
3
TEST
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4
SQL> select * from exitgogo8 where rownum<1;
未选定行
SQL> select * from exitgogo8 where rownum<2;
TEST
--------------------------------------------------------------------------------
1
SQL> select * from exitgogo8 where rownum<3;
TEST
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1
2
SQL> select * from exitgogo8 where rownum<4;
TEST
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1
2
3
TEST
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SQL> select * from exitgogo8 where rownum<=4;
TEST
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1
2
3
TEST
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4
SQL>
总结如下：
由此可见，只有当条件为rownum=1的时候才会有记录选出，其他数值均无选定行。
Oracle会给所有满足查询条件的记录指定一个顺序的数字（rownum）
对于满足的第一条记录
