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。你的php安装选项应该可以支持两者的使用。
连接
< ? 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$conn中。
查询
假设与数据库已经连接就绪，下面我们就来实际的应用对数据库的查询。下面的代码演示了一个连接并查询的典型例子：
function printoraerr($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)." ";
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($conn);
echo "logged off from oracle ";
?>
显示结果
以下代码演示了怎样查询数据库并将结果输出：
function printoraerr($in_cur, $conn)
{
// 检查oracle是否出错
// 如果存在错误则显示
// 当指针被激活时每次请求oracle后调用该函数
// if it encountered an error, we exit immediately
if(ora_errorcode($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);
// 显示头部
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");
$title="login instructions";
echo "
you are not authorized to enter the site
";
exit;
}
else
{
if (!($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;
}}
?>
