php數據庫連接
來源:程序員人生 發布時間:2013-12-14 19:34:47 閱讀次數:2853次
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。
4.1 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$conn中。
4.2 查詢
假設與數據庫已經連接就緒,下面我們就來實際的應用對數據庫的查詢。下面的代碼演示了一個連接并查詢的典型例子:
以下是引用片段:
-
-
-
- function printoraerr($in_cur)
- {
-
-
-
- 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($conn);
- echo "Logged off from oracle
- ";
- ?>
(譯者注:以上代碼段缺少注釋,請讀者參考PHP Manual的Oracle數據庫函數部分)
4.3 顯示結果
以下代碼演示了怎樣查詢數據庫并將結果輸出:以下是引用片段:
- function printoraerr($in_cur, $conn)
- {
-
-
-
-
- if(ora_errorcode($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);
-
- 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);
- }
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