用PHP連接Oracle數據庫

通過PHP你可以輕松的連接到數據庫，請求數據并將其顯示在你的web站點中，甚至修改數據庫中的數據。MySQL是一種很流行的數據庫，并且在互聯網中有許多有關PHP與MySQL的教程。MySQL是免費的，這一點也許就吸引了不少人。由于其廣泛應用，我就不想在這里贅述MySQL的使用方法了。Oracle被大量在企業應用中采用，因此我們就利用Oracle來介紹PHP與數據庫的連接。我們當然不會提及Oracle數據庫的設計原理，原因是這已經超出了我們的討論范圍。

　　PHP提供了兩套函數與Oracle連接，分別是ORA_和OCI函數。其中ORA_函數略顯陳舊。OCI函數更新據說更好一些。兩者的使用語法幾乎相差無幾。你的PHP安裝選項應該可以支持兩者的使用。

　　連接

<　? if ($conn=Ora_Logon("user@TNSNAME","password"))
{ echo "SUCCESS ! Connected to database ";
}else
{echo "Failed :-( Could not connect to database ";}
Ora_Logoff($conn);
phpinfo();
?>

　　以上代碼使用TNSNAME（在你的tnsnames.ora文件中指明）定義的Oracle數據庫名稱、用戶名稱和密碼連接數據庫。在成功連接的基礎上，ora_logon函數返回一個非零的連接ID并儲存在變量$conn中。

　　查詢

　　假設與數據庫已經連接就緒，下面我們就來實際的應用對數據庫的查詢。下面的代碼演示了一個連接并查詢的典型例子：

function printoraerr($in_cur)
{
// 檢查Oracle是否出錯
// 如果存在錯誤則顯示
// 當指針被激活時每次請求Oracle后調用該函數
if(ora_errorcode($in_cur))
echo "Oracle code - ".ora_error($in_cur)." ";
return;
}
if (!($conn=ora_logon("user@TNSNAME","password")))
{echo "Connection to database failed ";
exit;
}
echo "Connected as connection - $conn ";
echo "Opening cursor ... ";
$cursor=ora_open($conn); printoraerr($cursor);
echo "Opened cursor - $cursor ";
$qry="select user,sysdate from dual";
echo "Parsing the query $qry ... ";
ora_parse($cursor,$qry,0); printoraerr($cursor);
echo "Query parsed ";
echo "Executing cursor ... ";
ora_exec($cursor); printoraerr($cursor);
echo "Executed cursor ";
echo "Fetching cursor ... ";
while(ora_fetch($cursor))
{
$user=ora_getcolumn($cursor,0); printoraerr($cursor);
$sysdate=ora_getcolumn($cursor,1); printoraerr($cursor);
echo " row = $user, $sysdate ";
}
echo "Fetched all records ";
echo "Closing cursor ... ";
ora_close($cursor);
echo "Closed cursor ";
echo "Logging off from oracle... ";
ora_logoff($conn);
echo "Logged off from oracle ";
?>

　　顯示結果

　　以下代碼演示了怎樣查詢數據庫并將結果輸出：

function printoraerr($in_cur, $conn)
{
// 檢查Oracle是否出錯
// 如果存在錯誤則顯示
// 當指針被激活時每次請求Oracle后調用該函數
// If it encountered an error, we exit immediately
if(ora_errorcode($in_cur))
{echo "Oracle code - ".ora_error($in_cur)." n";
ora_logoff($conn);
exit;
}
return;
}

function exequery($w_qry,$conn)
{
$cursor=ora_open($conn); printoraerr($cursor,$conn);
ora_parse($cursor,$w_qry,0); printoraerr($cursor,$conn);
ora_exec($cursor); printoraerr($cursor,$conn);
$numrows=0;
$w_numcols=ora_numcols($cursor);
// 顯示頭部
echo " ";
for ($i=0;$i<$w_numcols;$i++)
{
$align=(ora_columntype($cursor,$i)=="NUMBER")?"RIGHT":"LEFT";
echo " ".ora_columnname($cursor,$i)." ";
}
echo " ";
while(ora_fetch($cursor))
{
echo " ";
for ($i=0;$i<$w_numcols;$i++)
{
$align=(ora_columntype($cursor,$i)=="NUMBER")?"RIGHT":"LEFT";
if(ora_columntype($cursor,$i)=="LONG")
echo " ".
ora_getcolumn($cursor,$i)." ";
else
echo " ".ora_getcolumn($cursor,$i)." ";
printoraerr($cursor,$conn);
}
$numrows++;
echo " ";
}
if ($numrows==0)
echo " Query returned no records ";
else
{
echo " ";
echo " Count ";
echo " $numrows ";
echo " ";
}
echo " ";
ora_close($cursor);
return;
}
// 主程序
if(!($conn=ora_logon("user@SID","password")))
{
echo "Error: Cannot connect to database ";
exit;
}
$qry="SELECT
deptno "Dept"
,empno "Emp"
,empnm "Name"
,salary "Salary"
FROM
employee
ORDER BY 1,2";
exequery($qry);
ora_logoff($conn);
?>


　　基于HTTP的Oracle登錄

　　將以下代碼加在PHP頁面代碼之前以確認Oracle登錄。注意你必須正確設定$ SID。

if(!isset($PHP_AUTH_USER))
{
Header("WWW-authenticate: basic realm="$SID"");
Header("HTTP/1.0 401 Unauthorized");
$title="Login Instructions";
echo "
You are not authorized to enter the site
";
exit;
}
else
{
if (!($conn=ora_logon("$PHP_AUTH_USER@$SID",$PHP_AUTH_PW)))
{Header("WWW-authenticate: basic realm="$SID"");
Header("HTTP/1.0 401 Unauthorized");
$title="Login Instructions";
echo "
You are not authorised to enter the site
";
exit;
}}
?>

原文轉自：http://www.kjueaiud.com