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。如前所述，你的PHP安裝選項應該可以支持兩者的使用。想獲得更多有關在Microsoft Windows平臺上安裝支持PHP3的Apache服務器的知識以及更多有關Oracle數據庫的知識，請查閱以下URL：www.csoft.net/~vsbabu/articles/oraphp.html。連接<? if ($conn=Ora_Logon("user@TNSNAME","password")) {echo "<B>SUCCESS ! Connected to database<B>n";} else {echo "<B>Failed :-( Could not connect to database<B>n";}Ora_Logoff($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$conn中。查詢假設與數據庫已經連接就緒，下面我們就來實際的應用對數據庫的查詢。下面的代碼演示了一個連接并查詢的典型例子：<?/** 連接數據庫并執行查詢*/function printoraerr($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)."n";return;}/** 主程序 */if (!($conn=ora_logon("user@TNSNAME","password"))) {echo "Connection to database failedn";exit;}echo "Connected as connection - <b>$conn</b><br>n";echo "Opening cursor ...<br>n";$cursor=ora_open($conn); printoraerr($cursor);echo "Opened cursor - <b>$cursor</b><br>n";$qry="select user,sysdate from dual";echo "Parsing the query <b>$qry</b> ...<br>n";ora_parse($cursor,$qry,0); printoraerr($cursor);echo "Query parsed <br>n";echo "Executing cursor ...<br>n";ora_exec($cursor); printoraerr($cursor);echo "Executed cursor<br>n";echo "Fetching cursor ...<br>n";while(ora_fetch($cursor)){$user=ora_getcolumn($cursor,0); printoraerr($cursor);$sysdate=ora_getcolumn($cursor,1); printoraerr($cursor);echo " row = <B>$user, $sysdate </B><br>n";}echo "Fetched all records<br>n";echo "Closing cursor ...<br>n";ora_close($cursor);echo "Closed cursor<br>n";echo "Logging off from oracle... <br>n";ora_logoff($conn);echo "Logged off from oracle <br>n";?>（譯者注：以上代碼段缺少注釋，請讀者參考PHP Manual的Oracle數據庫函數部分）顯示結果以下代碼演示了怎樣查詢數據庫并將結果輸出：<?function printoraerr($in_cur, $conn){// 檢查Oracle是否出錯// 如果存在錯誤則顯示// 當指針被激活時每次請求Oracle后調用該函數// If it encountered an error, we exit immediatelyif(ora_errorcode($in_cur)) {echo "Oracle code - ".ora_error($in_cur)."<br>n";ora_logoff($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 "<TABLE WIDTH="100%" BORDER="0" CELLSPACING="1" CELLPADDING="2"><TR>n";for ($i=0;$i<$w_numcols;$i++){$align=(ora_columntype($cursor,$i)=="NUMBER")?"RIGHT":"LEFT";echo "t<TH VALIGN=TOP ALIGN=$align>".ora_columnname($cursor,$i)."</TH>n";}echo "</TR>n";while(ora_fetch($cursor)){echo "<TR>n";for ($i=0;$i<$w_numcols;$i++) {$align=(ora_columntype($cursor,$i)=="NUMBER")?"RIGHT":"LEFT";if(ora_columntype($cursor,$i)=="LONG")echo "<TD VALIGN=TOP ALIGN=$align><PRE>".ora_getcolumn($cursor,$i)."</PRE></TD>n";elseecho "<TD VALIGN=TOP ALIGN=$align>".ora_getcolumn($cursor,$i)."</TD>n";printoraerr($cursor,$conn);}$numrows++;echo "</TR>n";}if ($numrows==0)echo "<TR><TD COLSPAN="$w_numcols"><B>Query returned no records</B></TD></TR>n";else {echo "<TR>n";echo "<TH COLSPAN="".($w_numcols-1)."" ALIGN=RIGHT>Count</TH>n";echo "<TH ALIGN=RIGHT>$numrows</TH>n";echo "</TR>n";}echo "</TABLE>n";ora_close($cursor);return;}// 主程序if(!($conn=ora_logon("user@SID","password"))) {echo "Error: Cannot connect to databasen";exit;}$qry="SELECTdeptno "Dept",empno "Emp",empnm "Name",salary "Salary"FROMemployeeORDER BY 1,2";exequery($qry);ora_logoff($conn);?>（譯者注：以上代碼段缺少注釋，請讀者參考PHP Manual的Oracle數據庫函數部分）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");$title="Login Instructions";echo "<blockquote>You are not authorized to enter the site</blockquote> n";exit;} else {if (!($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 "<blockquote>You are not authorised to enter the site</blockquote> n";exit;}}?>