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PHP与MYSQL数据库连接

浏览:2日期:2024-07-09 13:42:45
通过PHP你可以轻松的连接到数据库,请求数据并将其显示在你的web站点中,甚至修改数据库中的数据。MySQL是一种很流行的数据库,并且在互联网中有许多有关PHP与MySQL的教程。MySQL是免费的,这一点也许就吸引了不少人。由于其广泛应用,我就不想在这里赘述MySQL的使用方法了。Oracle被大量在企业应用中采用,因此我们就利用Oracle来介绍PHP与数据库的连接。我们当然不会提及Oracle数据库的设计原理,原因是这已经超出了我们的讨论范围。PHP提供了两套函数与Oracle连接,分别是ORA_和OCI函数。其中ORA_函数略显陈旧。OCI函数更新据说更好一些。两者的使用语法几乎相差无几。如前所述,你的PHP安装选项应该可以支持两者的使用。想获得更多有关在Microsoft Windows平台上安装支持PHP3的Apache服务器的知识以及更多有关Oracle数据库的知识,请查阅以下URL:www.csoft.net/~vsbabu/articles/oraphp.html。连接<? 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();?>以上代码使用TNSNAME(在你的tnsnames.ora文件中指明)定义的Oracle数据库名称、用户名称和密码连接数据库。在成功连接的基础上,ora_logon函数返回一个非零的连接ID并储存在变量$conn中。查询假设与数据库已经连接就绪,下面我们就来实际的应用对数据库的查询。下面的代码演示了一个连接并查询的典型例子:<?/** 连接数据库并执行查询*/function printoraerr($in_cur){// 检查Oracle是否出错// 如果存在错误则显示// 当指针被激活时每次请求Oracle后调用该函数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($conn);echo "Logged off from oracle <br>n";?>(译者注:以上代码段缺少注释,请读者参考PHP Manual的Oracle数据库函数部分)显示结果以下代码演示了怎样查询数据库并将结果输出:<?function printoraerr($in_cur, $conn){// 检查Oracle是否出错// 如果存在错误则显示// 当指针被激活时每次请求Oracle后调用该函数// If it encountered an error, we exit immediatelyif(ora_errorcode($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);// 显示头部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);?>(译者注:以上代码段缺少注释,请读者参考PHP Manual的Oracle数据库函数部分)基于HTTP的Oracle登录将以下代码加在PHP页面代码之前以确认Oracle登录。注意你必须正确设定$ 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;}}?>
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