ORACLE ÈçºÎ²úÉúÒ»¸öËæ»úÊý
ORACLE ÈçºÎ²úÉúÒ»¸öËæ»úÊý:DBMS_RANDOM
--1¡¢Ð¡Êý( 0 ~ 1)
select dbms_random.value from dual ;
--2¡¢Ö¸¶¨·¶Î§ÄÚµÄСÊý ( 0 ~ 100 )
select dbms_random.value(0,100) from dual ;
--3¡¢Ö¸¶¨·¶Î§ÄÚµÄÕûÊý ( 0 ~ 100 )
select trunc(dbms_random.value(0,100)) from dual ;
--4¡¢³¤¶ÈΪ20µÄËæ»úÊý×Ö´®
select substr(cast(dbms_random.value as varchar2(38)),0,10) from dual ;
--5¡¢Õý̬·Ö²¼µÄËæ»úÊý
select dbms_random.normal from dual ;
--6¡¢Ëæ»ú×Ö·û´®
select dbms_random.string('x', 3) from dual ;
/* opt¿ÉȡֵÈçÏ£º
'u','U' : ´óд×Öĸ
'l','L' : Сд×Öĸ
'a','A' : ´ó¡¢Ð¡Ð´×Öĸ
'x','X' : Êý×Ö¡¢´óд×Öĸ
'p','P' : ¿É´òÓ¡×Ö·û*/
--7¡¢Ëæ»úÈÕÆÚ
select to_date(2454084+TRUNC(DBMS_RANDOM.VALUE(0,365)),'J') from dual ;
/* ͨ¹ýÏÂÃæµÄÓï¾ä»ñµÃÖ¸¶¨ÈÕÆÚµÄ»ùÊý*/
select to_char(sysdate,'J') from dual ;
--8¡¢Éú³ÉGUID
select sys_guid() from dual ;
--Éú³É´ø·Ö¸ô·û(-)µÄGUIDµÄ×Ô¶¨Ò庯Êý
--create or replace function my_guid
return varchar2
is
guid varchar(36);
temp varchar(32);
begin
temp:=sys_guid();
guid:= substr(temp,1,8) || '-'
||substr(temp,9,4) || '-'
||substr(temp,13,4)|| '-'
||substr(temp,17,4)|| '-'
||substr(temp,21,12)
Ïà¹ØÎĵµ£º
ÓÐÁ½ÖÖº¬ÒåµÄ±í´óС¡£Ò»ÖÖÊÇ·ÖÅä¸øÒ»¸ö±íµÄÎïÀí¿Õ¼äÊýÁ¿£¬¶ø²»¹Ü¿Õ¼äÊÇ·ñ±»Ê¹Ó᣿ÉÒÔÕâÑù²éѯ»ñµÃ×Ö½ÚÊý£º
select segment_name, bytes
from user_segments
where segment_type = 'TABLE';
»òÕß
Select Segment_Name,Sum(bytes)/1024/1024 from User_Extents Group By Segment_Name
ÁíÒ»ÖÖ±íʵ¼ÊÊ¹Ó ......
dc-test2<oracle>sqlplus /nolog
SQL*Plus: Release 10.2.0.4.0 - Production on Thu Feb 25 19:23:35 2010
Copyright (c) 1982, 2007, Oracle. All Rights Reserved.
SQL> desc v$datafile;
SP2-0640: Not connected
SP2-0641: "DESCRIBE" requires connection to server
SQL> conn / a ......
dc-test2<oracle>sqlplus /nolog
SQL*Plus: Release 10.2.0.4.0 - Production on Thu Feb 25 22:44:25 2010
Copyright (c) 1982, 2007, Oracle. All Rights Reserved.
SQL> conn / as sysdba
Connected.
SQL> define
DEFINE _DATE = ......
OracleÈÕÆÚº¯Êý¼¯½õ(Ò»)
Ò»¡¢ ³£ÓÃÈÕÆÚÊý¾Ý¸ñʽ
1.Y»òYY»òYYY ÄêµÄ×îºóһ룬Á½Î»»òÈýλ
SQL> Select to_char(sysdate,'Y') from dual;
TO_CHAR(SYSDATE,'Y')
--------------------
7
SQL> Select to_char(sysdate,'YY') from dual;
TO_CHAR(SYSDATE,'YY')
---------------------
07
SQL> Select to_ch ......