[CSS] a:link,a:visited,a:hover,a:active order
a:link {color: #FF0000} /* unvisited link */
a:visited {color: #00FF00} /* visited link */
a:hover {color: #FF00FF} /* mouse over link */
a:active {color: #0000FF} /* selected link */
PHP Shell Script
We can use php as a shell script by adding the line below at the top of the php script file.
#!/usr/local/bin/php -Cq
C means do not change working directory to that of the script.
q means do not send HTTP header.
There is a reference manual 『Using PHP from the command line』 in php.net
在Oracle中找出重複的紀錄的方法
在Oracle中找出重複的紀錄的方法
SELECT aid FROM atable GROUP BY aid HAVING COUNT(*) >1;
刪除重複的記錄
DELETE FROM atable a where a.ROWID!=(SELECT MAX(ROWID) FROM atable b WHERE a.aid=b.aid;
在ORACLE/PLSQL裡使用游標FOR迴圈(cursor FOR loop)
藉由從abc_stu資料表內抓取該學號的生日，來更新stu資料表裡每個學號的生日。
DECLARE
CURSOR cur IS
SELECT stuid FROM stu;
BEGIN
FOR rec IN cur
LOOP
UPDATE stu
SET (birth_yr,birth_mm,birth_dd)=
(SELECT birth_yr,birth_mm,birth_dd FROM abc_stu WHERE stuid=rec.stuid)
WHERE stuid=rec.stuid;
END LOOP;
END;
Oracle/PLSQL: If Exists Update Else Insert
If data exists then update it, otherwise insert it.
In Oracle/PLSQL
BEGIN
UPDATE TABLE_NAME SET COL=’a’ WHERE ID=’foobar’;
IF sql%rowcount = 0 THEN
INSERT INTO TABLE_NAME (ID,COL) VALUES(‘foobar’,'a’);
END IF;
END;
some problem with PHP SESSION Array
session_test.php
<?php
session_start();
$_SESSION['IDNO']=’A1234′;
$_SESSION['DPT_COD'][0]=’1402′;
$_SESSION['DPT_COD'][1]=’B402′;
Print_r($_SESSION);
echo 『<br /><a href=』session_test2.php』>next!</a>』;
?>
The browser show:
Array ( [IDNO] => A1234 [DPT_COD] => Array ( [0] => 1402 [1] => B402 ) )
next!
session_test2.php
<?php
session_start();
echo 『Original SESSION array values:<br />』;
Print_r($_SESSION);
echo 『<br /><br />』;echo 『New SESSION array values:<br />』;
$IDNO=’Z5678′;
$DPT_COD=’foobar’;
Print_r($_SESSION);session_unset();
session_destroy();
?>
In machine 1
The browser show:
Original SESSION array values:
Array ( [IDNO] => A1234 [DPT_COD] => Array ( [0] => 1402 [1] => B402 ) )
New SESSION array values:
Array ( [IDNO] => Z5678 [DPT_COD] => foobar )
In machine 2
The browser show:
Original SESSION array values:
Array ( [IDNO] => A1234 [DPT_COD] => Array ( [0] => 1402 [1] => B402 ) )
New SESSION array values:
Array ( [IDNO] => A1234 [DPT_COD] => Array ( [0] => 1402 [1] => B402 ) )
I think the result in machine 2 is what it should be.
But I don’t know why macheine 1 show that diffrent result.
The answer is someone turn on register_globals in php.ini in machine 1.
Oracle中設定auto increment的一些相關筆記
清空資料表
truncate table TABLE_NAME;
設定Auto Increment
參考資料：
http://www.lifeaftercoffee.com/2006/02/17/how-to-create-auto-increment-columns-in-oracle/
先建立一個sequence
create sequence SEQUENCE_NAME
start with 1
increment by 1
nocache;
再建立一個trigger
create or replace trigger TRIGGER_NAME
before insert
on TABLE_NAME
referencing NEW as NEW
for each row
begin
select SEQUENCE_NAME.nextval into :NEW.AUTO_INCREMENT_COLUMN from dual;
end;
/
這樣就完成了
SEQUENCE有下列參數：MINVALUE、MAXVALUE、START WITH、INCREMENT BY、CACHE、NOCACHE、CYCLE
要加nocache，sequence才不會亂跳
SEQUENCE到達最大值之前不能重新計數，只能用DROP刪除後再重新CREATE建立。
可以用ALTER來修改SEQUENCE的參數
ALTER SEQUENCE seq01
INCREMENT BY 100;
用NEXTVAL取得下一個值
SELECT seq01.NEXTVAL FROM DUAL;
用CURRVAL取的目前值
SELECT seq01.CURRVAL FROM DUAL;
Gentoo的套件透過emerge更新時的注意事項
根據CD長輩的教誨
首先
emerge -DuN world
接著
emerge –depclean
最後
revdep-rebuild
這期間如有套件出錯，則
emerge –oneshot 套件
這樣可重編一次該套件，卻不把該套件加入world list裡。
IPv6, openssh, and tcp_wrappers
在一台新重灌好的Gentoo server裡編了IPv6的支援，在開啟openssh時，會有
refused connect from 0.0.0.0
這樣的error message出現，tcp_wrappers的hosts.deny運作也不太正常。
後來找到解決方法為，讓openssh只使用IPv4，在/etc/ssh/sshd_config裡做了以下設定即可
AddressFamily inet
