php數(shù)據(jù)庫(kù)連接
來(lái)源:程序員人生 發(fā)布時(shí)間:2013-12-14 19:34:47 閱讀次數(shù):2857次
通過(guò)PHP你可以輕松的連接到數(shù)據(jù)庫(kù),請(qǐng)求數(shù)據(jù)并將其顯示在你的web站點(diǎn)中,甚至修改數(shù)據(jù)庫(kù)中的數(shù)據(jù)。MySQL是一種很流行的數(shù)據(jù)庫(kù),并且在互聯(lián)網(wǎng)中有許多有關(guān)PHP與MySQL的教程。MySQL是免費(fèi)的,這一點(diǎn)也許就吸引了不少人。由于其廣泛應(yīng)用,我就不想在這里贅述MySQL的使用方法了。Oracle被大量在企業(yè)應(yīng)用中采用,因此我們就利用Oracle來(lái)介紹PHP與數(shù)據(jù)庫(kù)的連接。我們當(dāng)然不會(huì)提及Oracle數(shù)據(jù)庫(kù)的設(shè)計(jì)原理,原因是這已經(jīng)超出了我們的討論范圍。
PHP提供了兩套函數(shù)與Oracle連接,分別是ORA_和OCI函數(shù)。其中ORA_函數(shù)略顯陳舊。OCI函數(shù)更新?lián)f(shuō)更好一些。兩者的使用語(yǔ)法幾乎相差無(wú)幾。如前所述,你的PHP安裝選項(xiàng)應(yīng)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(shù)據(jù)庫(kù)名稱(chēng)、用戶(hù)名稱(chēng)和密碼連接數(shù)據(jù)庫(kù)。在成功連接的基礎(chǔ)上,ora_logon函數(shù)返回一個(gè)非零的連接ID并儲(chǔ)存在變量$conn中。
4.2 查詢(xún)
假設(shè)與數(shù)據(jù)庫(kù)已經(jīng)連接就緒,下面我們就來(lái)實(shí)際的應(yīng)用對(duì)數(shù)據(jù)庫(kù)的查詢(xún)。下面的代碼演示了一個(gè)連接并查詢(xún)的典型例子:
以下是引用片段:
-
-
-
- function printoraerr($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($conn);
- echo "Logged off from oracle
- ";
- ?>
(譯者注:以上代碼段缺少注釋?zhuān)?qǐng)讀者參考PHP Manual的Oracle數(shù)據(jù)庫(kù)函數(shù)部分)
4.3 顯示結(jié)果
以下代碼演示了怎樣查詢(xún)數(shù)據(jù)庫(kù)并將結(jié)果輸出:以下是引用片段:
- function printoraerr($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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