oci_pconnect

(PHP 5, PECL OCI8 >= 1.1.0)

oci_pconnect — Connect to an Oracle database using a persistent connection

說明

resource oci_pconnect ( string $username , string $password [, string $connection_string [, string $character_set [, int $session_mode ]]] )

Creates a persistent connection to an Oracle server and logs on.

Persistent connections are cached and re-used between requests, resulting in reduced overhead on each page load; a typical PHP application will have a single persistent connection open against an Oracle server per Apache child process (or PHP FastCGI/CGI process). See the Persistent Database Connections section for more information.

參數

username

The Oracle user name.

password

The password for username.

connection_string

包含要連接的 Oracle 實例。可以是 » Easy Connect 字串，或是 tnsnames.ora 文件中的連接名，或是本地 Oracle 實體名。

如果不指定，PHP 使用環境變數來確定連接的 Oracle 實例，諸如 TWO_TASK（Linux 下）或 LOCAL（Windows 下）與 ORACLE_SID 等。

要使用 Easy Connect 命名方法，PHP 必須與 Oracle 10g 或更高版本的客戶端函式庫進行連結。Oracle 10g 的 Easy Connect 字串格式：[//]host_name[:port][/service_name]。Oracle 11g 則為：[//]host_name[:port][/service_name][:server_type][/instance_name]。服務名可在資料庫伺服器機器上執行 Oracle 工具程式 lsnrctl status 找到。

tnsnames.ora 檔案可在 Oracle Net 尋找路徑中，此路徑包括 $ORACLE_HOME/network/admin 和 /etc。另一種方法是設定 TNS_ADMIN 以便通過 $TNS_ADMIN/tnsnames.ora 來讀取。表確認 web 背景程序可讀取此文件。

character_set

使用 Oracle 客戶端函式庫來確定字元集。字元集不需要與資料庫的字符集相匹配。如果不匹配，Oracle 會儘可能地將資料從資料庫字元集進行轉換。因為依賴於字元集，可能不能給出可用的結果。轉換也增加一些時間。

如果不指定，Oracle 客戶端用 NLS_LANG 環境變數來決定字元集。

傳遞此參數可減少連接時間。

session_mode

此參數在 PHP 5（PECL OCI8 1.1）版本開始可用，並接受下列值：OCI_DEFAULT，OCI_SYSOPER 和 OCI_SYSDBA。如為 OCI_SYSOPER 或 OCI_SYSDBA 其中之一，此函式將會使用外部的憑證建立有特權的連結。有特權的連結預設是禁用的。需要將 oci8.privileged_connect 設為 On 來啟用。

PHP 5.3（PECL OCI8 1.3.4）引進了 OCI_CRED_EXT 模式值。使用外部或操作系統認證必需在 Oracle 資料庫中進行設定。OCI_CRED_EXT 標誌只可用於用戶為 "/"，密碼為空的情況。oci8.privileged_connect 可為 On 或 Off。

OCI_CRED_EXT 可與 OCI_SYSOPER 或 OCI_SYSDBA 模式組合使用。

OCI_CRED_EXT 由於安全的原因不支援 Windows 系統。

回傳值

Returns a connection identifier or FALSE on error.

範例

Example #1 Basic oci_pconnect() Example using Easy Connect syntax


<?php

// Connects to the XE service (i.e. database) on the "localhost" machine
$conn = oci_pconnect('hr', 'welcome', 'localhost/XE');
if (!$conn) {
    $e = oci_error();
    trigger_error(htmlentities($e['message'], ENT_QUOTES), E_USER_ERROR);
}

$stid = oci_parse($conn, 'SELECT * FROM employees');
oci_execute($stid);

echo "<table border='1'>\n";
while ($row = oci_fetch_array($stid, OCI_ASSOC+OCI_RETURN_NULLS)) {
    echo "<tr>\n";
    foreach ($row as $item) {
        echo "    <td>" . ($item !== null ? htmlentities($item, ENT_QUOTES) : "&nbsp;") . "</td>\n";
    }
    echo "</tr>\n";
}
echo "</table>\n";

?>

See oci_connect() for further examples of parameter usage.

註釋

Note: Starting with PHP 5.1.2 and PECL OCI8 1.1, the lifetime and maximum number of persistent Oracle connections per PHP process can be tuned by setting the following configuration values: oci8.persistent_timeout, oci8.ping_interval and oci8.max_persistent.

參見

oci_connect() - Connect to an Oracle database
oci_new_connect() - Connect to the Oracle server using a unique connection

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User Contributed Notes 2 notes

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php at jaggard dot org dot uk ¶

15 years ago


[Editor's note: OCI8 1.3 should not experience the problem described in this user comment. The first use of such a connection will return an Oracle error which will trigger a cleanup in PHP.  Subsequent persistent connection calls will then succeed.  For high availability you might consider doing consecutive oci_pconnect calls in your script.]



If you connect using oci_pconnect and the connection has logged you off but is still valid, there seems to be no way to re-use that connection. The next time I try oci_pconnect and then perform an oci_execute operation, I get a "ORA-01012: not logged on" warning. This problem remains, even if I close the connection using oci_close. I ended up with the following (rather annoying) code.



<?php

    function getOracleConnection()

    {

      if (!function_exists('oci_pconnect'))

        return false;

      $toReturn = oci_pconnect('user', 'pass', 'db');

      if ($testRes = @oci_parse($toReturn, 'SELECT Count(group_type_code) FROM pvo.group_type'))

        if (@oci_execute($testRes))

          if (@oci_fetch_array($testRes))

            return $toReturn;

      oci_close($toReturn);

      if (!function_exists('oci_connect'))

        return false;

      $toReturn = oci_connect('user', 'pass', 'db');

      if ($testRes = @oci_parse($toReturn, 'SELECT Count(group_type_code) FROM pvo.group_type'))

        if (@oci_execute($testRes))

          if (@oci_fetch_array($testRes))

            return $toReturn;

      oci_close($toReturn);

      if (!function_exists('oci_new_connect'))

        return false;

      $toReturn = oci_new_connect('user', 'pass', 'db');

      if ($testRes = @oci_parse($toReturn, 'SELECT Count(group_type_code) FROM pvo.group_type'))

        if (@oci_execute($testRes))

          if (@oci_fetch_array($testRes))

            return $toReturn;

      oci_close($toReturn);

      return false;

    }

?>

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gotankersley at NOSPAM dot com ¶

11 years ago


Installed on CentOS 6.2, and had lots of trouble getting it to recognize tnsnames.ora.  The fix for me was:

1. Make sure apache is getting the TNS_ADMIN env variable by putting it in the /etc/init.d/httpd file:
 TNS_ADMIN=/usr/lib/oracle/11.2/client64/network/admin
 export PATH TNS_ADMIN

This can be debugging in PHP by <?php echo system('env'); ?> and by verifying that TNS_ADMIN is there.

2. Make sure to use the name at the beginning of the tnsnames.ora file - not the SID (although ideally they should match.  However, if the name at the beginning is XXXX.world then pconnect will expect this - not the SID)

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