4.与数据库的连接

}

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 - $conn
\n";

echo "Opening cursor ...
\n";

$cursor=ora_open($conn); printoraerr($cursor);

echo "Opened cursor - $cursor
\n";

$qry="select user,sysdate from dual";

echo "Parsing the query $qry ...
\n";

ora_parse($cursor,$qry,0); printoraerr($cursor);

echo "Query parsed
\n";

echo "Executing cursor ...
\n";

ora_exec($cursor); printoraerr($cursor);

echo "Executed cursor
\n";

echo "Fetching cursor ...
\n";

while(ora_fetch($cursor))

{

$user=ora_getcolumn($cursor,0); printoraerr($cursor);

$sysdate=ora_getcolumn($cursor,1); printoraerr($cursor);

echo " row = $user, $sysdate
\n";

}

echo "Fetched all records
\n";

echo "Closing cursor ...
\n";

ora_close($cursor);

echo "Closed cursor
\n";

echo "Logging off from oracle...
\n";

ora_logoff($conn);

echo "Logged off from oracle
\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)."
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\">

for ($i=0;$i<$w_numcols;$i++)

{

$align=(ora_columntype($cursor,$i)=="NUMBER")?"RIGHT":"LEFT";

echo "\t".ora_columnname($cursor,$i)."\n";

}

echo "\n";

while(ora_fetch($cursor))

{

echo "\n";

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)."\n";

printoraerr($cursor,$conn);

}

$numrows++;

echo "\n";

}

if ($numrows==0)

echo "<TD COLSPAN=\"$w_numcols\">Query
returned no records

\n";

else

{

echo "\n";

echo "<TH COLSPAN=\"".($w_numcols-1)."\" ALIGN=RIGHT>Count\n";

echo "$numrows\n";

echo "\n";

}

echo "\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 "

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;

}

}

?>