Oracle中生成uuid的方法

Oracle中生成uuid的方法


  下載LOFTER客戶端 
在Oracle SQL 提供了一個生成uuid的函數sys_guid:
http://download.oracle.com/docs/cd/E11882_01/server.112/e17118/functions187.htm#i79194
http://en.wikipedia.org/wiki/Universally_unique_identifier


SQL> select sys_guid() from dual ;
SYS_GUID()
--------------------------------
A8F662B86E7413FEE040970A437C6BD7


但該函數如下問題：
     1.返回類型為RAW
     2.沒有- (dash)分隔符
     3.返回的字母大寫


為了使產生的uuid符合rfc 4122的標准(http://tools.ietf.org/html/rfc4122)
創建函數如下，測試通過。


CREATE OR REPLACE
FUNCTION get_uuid
RETURN VARCHAR
IS
guid VARCHAR (50);
BEGIN
guid := lower(RAWTOHEX(sys_guid()));
RETURN
substr(guid,1,8)||'-'||substr(guid,9,4)||'-'||substr(guid,13,4)||'-'||substr(guid,17,4)||'-'||substr(guid,21,12);
END get_uuid;


SQL> select get_uuid from dual ;


GET_UUID
--------------------------------------------------------------------------------
a8f662b8-6e7a-13fe-e040-970a437c6bd7


SQL> /


GET_UUID
--------------------------------------------------------------------------------
a8f662b8-6e7b-13fe-e040-970a437c6bd7


SQL> /


GET_UUID
--------------------------------------------------------------------------------
a8f662b8-6e7c-13fe-e040-970a437c6bd7