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select * from emp where rownum
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 > 5 
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1 Oracle
 executes your query.
2 Oracle
 fetches the first row and calls it row number 1.
3 Have we gotten past row number meets the criteria? If no, then Oracle
 discards the row, If yes, thenOracle
 return the row.
4 Oracle
 fetches the next row and advances the row number (to 2, and then to 3, and then to 4, and so forth).
5 Go to step 3.
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=1ʱ²ÅÓÐÓá£
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ID¡¡¡¡¡¡    char(6)¡¡¡¡¡¡¡¡¡¡ --ѧºÅ
name¡¡¡¡¡¡¡¡VARCHAR2(10)¡¡¡¡¡¡--ÐÕÃû create table student (ID char(6), name VARCHAR2(100));
insert into sale values('200001',‘ÕÅÒ»’);
insert into sale values('200002',‘Íõ¶þ’);
insert into sale values('200003',‘ÀîÈý’);
insert into sale values('200004',‘ÕÔËÄ’);
commit;
(1) rownum
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=1×÷ΪÌõ¼þ¡£µ«ÊÇÏëÕÒµ½Ñ§Éú±íÖеڶþÌõѧÉúµÄÐÅÏ¢£¬Ê¹ÓÃrownum
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IF Ìõ¼þ=Öµ1 THEN
¡¡¡¡¡¡¡¡RETURN(·­ÒëÖµ1)
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JDBC´æÈ¡ORACLE´óÐÍÊý¾Ý¶ÔÏóLOB¼¸ÖÖÇé¿öµÄʾ·¶Àà

      import Java.io.*;
¡¡¡¡import java.util.*;
¡¡¡¡import java.sql.*;
¡¡¡¡public class LobPros
¡¡¡¡{
¡¡¡¡/**
¡¡¡¡* OracleÇý¶¯³ÌÐò
¡¡¡¡*/
¡¡¡¡private static final String DRIVER = "oracle.jdbc.driver.OracleDriver";
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