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。

4.1 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。

4.2 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 failed\n";
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）

4.3 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)."<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";
else
echo "<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 database\n";
exit;
}
＄qry="SELECT
deptno \"Dept\"
,empno \"Emp\"
,empnm \"Name\"
,salary \"Salary\"
FROM
employee
ORDER 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）

4.4 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;
}
}
?>