oci_connect

(PHP 5, PHP 7, PECL OCI8 >= 1.1.0)

oci_connect建立一个到 Oracle 服务器的连接

说明

oci_connect ( string $username , string $password [, string $db [, string $charset [, int $session_mode ]]] ) : resource

oci_connect() 返回一个大多数 OCI 调用都需要的连接标识符。可选的第三个参数可以包含想要连接的本地 Oracle 的实例的或者在 tnsnames.ora 中的条目的名字。如果没有指定可选的第三个参数,PHP 使用环境变量 ORACLE_SID(Oracle 实例)或 TWO_TASKtnsnames.ora)来确定连接哪一个数据库。

session_mode 参数自版本 1.1 起可用并接受如下值:OCI_DEFAULTOCI_SYSOPEROCI_SYSDBA。如果指定了 OCI_SYSOPEROCI_SYSDBA 其中之一,oci_connect() 将尝试使用外部认证信息建立特权连接。特权连接默认被禁止。要启用,需要将 oci8.privileged_connect 设为 On。

Note: oci_connect() 用同样的参数第二次及之后的调用将返回第一次调用所返回的连接句柄。也就是说对一个句柄发出的查询也适用于另一个句柄,因为它们是同一个句柄。此行为演示于下面的例 1。如果需要两个句柄在事务上互相隔离开,应该使用 oci_new_connect() 来替代。

使用 Oracle 客户端库来确定字符集。字符集不需要与数据库的字符集相匹配。如果不匹配,Oracle 会尽可能地将数据从数据库字符集进行转换。因为依赖于字符集,可能不能给出可用的结果。转换也增加一些时间开销。

如果不指定,Oracle 客户端用 NLS_LANG 环境变量来决定字符集。

传递此参数可减少连接时间。

Example #1 oci_connect() 例子

<?php
echo "<pre>";
$db "";

$c1 oci_connect("scott""tiger"$db);
$c2 oci_connect("scott""tiger"$db);

function 
create_table($conn)
{
  
$stmt oci_parse($conn"create table scott.hallo (test varchar2(64))");
  
oci_execute($stmt);
  echo 
$conn " created table\n\n";
}

function 
drop_table($conn)
{
  
$stmt oci_parse($conn"drop table scott.hallo");
  
oci_execute($stmt);
  echo 
$conn " dropped table\n\n";
}

function 
insert_data($conn)
{
  
$stmt oci_parse($conn"insert into scott.hallo
            values('
$conn' || ' ' || to_char(sysdate,'DD-MON-YY HH24:MI:SS'))");
  
oci_execute($stmtOCI_DEFAULT);
  echo 
$conn " inserted hallo\n\n";
}

function 
delete_data($conn)
{
  
$stmt oci_parse($conn"delete from scott.hallo");
  
oci_execute($stmtOCI_DEFAULT);
  echo 
$conn " deleted hallo\n\n";
}

function 
commit($conn)
{
  
oci_commit($conn);
  echo 
$conn " committed\n\n";
}

function 
rollback($conn)
{
  
oci_rollback($conn);
  echo 
$conn " rollback\n\n";
}

function 
select_data($conn)
{
  
$stmt oci_parse($conn"select * from scott.hallo");
  
oci_execute($stmtOCI_DEFAULT);
  echo 
$conn."----selecting\n\n";
  while (
oci_fetch($stmt)) {
    echo 
$conn " [" oci_result($stmt"TEST") . "]\n\n";
  }
  echo 
$conn "----done\n\n";
}

create_table($c1);
insert_data($c1);   // Insert a row using c1
insert_data($c2);   // Insert a row using c2

select_data($c1);   // Results of both inserts are returned
select_data($c2);

rollback($c1);      // Rollback using c1

select_data($c1);   // Both inserts have been rolled back
select_data($c2);

insert_data($c2);   // Insert a row using c2
commit($c2);        // Commit using c2

select_data($c1);   // Result of c2 insert is returned

delete_data($c1);   // Delete all rows in table using c1
select_data($c1);   // No rows returned
select_data($c2);   // No rows returned
commit($c1);        // Commit using c1

select_data($c1);   // No rows returned
select_data($c2);   // No rows returned

drop_table($c1);
echo 
"</pre>";
?>

oci_connect() 如果出错则返回 FALSE

Note:

在 PHP 5.0.0 之前的版本必须使用 ocilogon() 替代本函数。该函数名仍然可用,为向下兼容作为 oci_connect() 的别名。不过其已被废弃,不推荐使用。

参见 oci_pconnect()oci_new_connect()oci_close()

参数

username

The Oracle user name.

password

The password for username.

connection_string

包含要连接的 Oracle 实例。可以是 » Easy Connect 串,或是 tnsnames.ora 文件中的连接名,或是本地 Oracle 实例名。

如果不指定,PHP 使用环境变量来确定连接的 Oracle 实例,诸如 TWO_TASK(Linux 下)或 LOCAL(Windows 下)与 ORACLE_SID 等。

要使用 Easy Connect 命名方法,PHP 必须与 Oracle 10g 或更高版本的客户端库进行链接。Oracle 10g 的 Easy Connect 串格式:[//]host_name[:port][/service_name]。Oracle 11g 则为:[//]host_name[:port][/service_name][:server_type][/instance_name]。服务名可在数据库服务器机器上运行 Oracle 实用程序 lsnrctl status 找到。

tnsnames.ora 文件可在 Oracle Net 查找路径中,此路径包括 $ORACLE_HOME/network/admin/etc。 另一种方法是设置 TNS_ADMIN 以便通过 $TNS_ADMIN/tnsnames.ora 来读取。表确认 web 守护进程可读取此文件。

character_set

使用 Oracle 客户端库来确定字符集。字符集不需要与数据库的字符集相匹配。如果不匹配,Oracle 会尽可能地将数据从数据库字符集进行转换。因为依赖于字符集,可能不能给出可用的结果。转换也增加一些时间开销。

如果不指定,Oracle 客户端用 NLS_LANG 环境变量来决定字符集。

传递此参数可减少连接时间。

session_mode

此参数在 PHP 5(PECL OCI8 1.1)版本开始可用,并收受下列值:OCI_DEFAULTOCI_SYSOPEROCI_SYSDBA。如为 OCI_SYSOPEROCI_SYSDBA 其中之一,此函数将会使用外部的证书建立有特权的连接。有特权的连接默认是禁用的。需要将 oci8.privileged_connect 设为 On 来启用。

PHP 5.3(PECL OCI8 1.3.4)引进了 OCI_CRED_EXT 模式值。使用外部或操作系统认证必需在 Oracle 数据库中进行配置。OCI_CRED_EXT 标志只可用于用户为 "/",密码为空的情况。oci8.privileged_connect 可为 OnOff

OCI_CRED_EXT 可与 OCI_SYSOPEROCI_SYSDBA 模式组合使用。

OCI_CRED_EXT 由于安全的原因不支持 Windows 系统。

返回值

Returns a connection identifier or FALSE on error.

范例

Example #2 Basic oci_connect() using Easy Connect syntax

<?php

// Connects to the XE service (i.e. database) on the "localhost" machine
$conn oci_connect('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 (
$row oci_fetch_array($stidOCI_ASSOC+OCI_RETURN_NULLS)) {
    echo 
"<tr>\n";
    foreach (
$row as $item) {
        echo 
"    <td>" . ($item !== null htmlentities($itemENT_QUOTES) : "&nbsp;") . "</td>\n";
    }
    echo 
"</tr>\n";
}
echo 
"</table>\n";

?>

Example #3 Basic oci_connect() using a Network Connect name

<?php

// Connects to the MYDB database described in tnsnames.ora file,
// One example tnsnames.ora entry for MYDB could be:
//   MYDB =
//     (DESCRIPTION =
//       (ADDRESS = (PROTOCOL = TCP)(HOST = mymachine.oracle.com)(PORT = 1521))
//       (CONNECT_DATA =
//         (SERVER = DEDICATED)
//         (SERVICE_NAME = XE)
//       )
//     )

$conn oci_connect('hr''welcome''MYDB');
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 (
$row oci_fetch_array($stidOCI_ASSOC+OCI_RETURN_NULLS)) {
    echo 
"<tr>\n";
    foreach (
$row as $item) {
        echo 
"    <td>" . ($item !== null htmlentities($itemENT_QUOTES) : "&nbsp;") . "</td>\n";
    }
    echo 
"</tr>\n";
}
echo 
"</table>\n";

?>

Example #4 oci_connect() with an explicit character set

<?php

$conn 
oci_connect('hr''welcome''localhost/XE''AL32UTF8');
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 (
$row oci_fetch_array($stidOCI_ASSOC+OCI_RETURN_NULLS)) {
    echo 
"<tr>\n";
    foreach (
$row as $item) {
        echo 
"    <td>" . ($item !== null htmlentities($itemENT_QUOTES) : "&nbsp;") . "</td>\n";
    }
    echo 
"</tr>\n";
}
echo 
"</table>\n";

?>

Example #5 Using multiple calls to oci_connect()

<?php

$c1 
oci_connect("hr""welcome"'localhost/XE');
$c2 oci_connect("hr""welcome"'localhost/XE');

// Both $c1 and $c2 show the same PHP resource id meaning they use the
// same underlying database connection
echo "c1 is $c1<br>\n";
echo 
"c2 is $c2<br>\n";

function 
create_table($conn)
{
    
$stmt oci_parse($conn"create table hallo (test varchar2(64))");
    
oci_execute($stmt);
    echo 
"Created table<br>\n";
}

function 
drop_table($conn)
{
    
$stmt oci_parse($conn"drop table hallo");
    
oci_execute($stmt);
    echo 
"Dropped table<br>\n";
}

function 
insert_data($connname$conn)
{
    
$stmt oci_parse($conn"insert into hallo
              values(to_char(sysdate,'DD-MON-YY HH24:MI:SS'))"
);
    
oci_execute($stmtOCI_DEFAULT);
    echo 
"$connname inserted row without committing<br>\n";
}

function 
rollback($connname$conn)
{
    
oci_rollback($conn);
    echo 
"$connname rollback<br>\n";
}

function 
select_data($connname$conn)
{
    
$stmt oci_parse($conn"select * from hallo");
    
oci_execute($stmtOCI_DEFAULT);
    echo 
"$connname ----selecting<br>\n";
    while (
oci_fetch($stmt)) {
        echo 
"    " oci_result($stmt"TEST") . "<br>\n";
    }
    echo 
"$connname ----done<br>\n";
}

create_table($c1);

insert_data('c1'$c1);   // Insert a row using c1
sleep(2);                 // sleep to show a different timestamp for the 2nd row
insert_data('c2'$c2);   // Insert a row using c2

select_data('c1'$c1);   // Results of both inserts are returned
select_data('c2'$c2);   // Results of both inserts are returned

rollback('c1'$c1);      // Rollback using c1

select_data('c1'$c1);   // Both inserts have been rolled back
select_data('c2'$c2);

drop_table($c1);

// Closing one of the connections makes the PHP variable unusable, but
// the other could be used
oci_close($c1);
echo 
"c1 is $c1<br>\n";
echo 
"c2 is $c2<br>\n";


// Output is:
//    c1 is Resource id #5
//    c2 is Resource id #5
//    Created table
//    c1 inserted row without committing
//    c2 inserted row without committing
//    c1 ----selecting
//        09-DEC-09 12:14:43
//        09-DEC-09 12:14:45
//    c1 ----done
//    c2 ----selecting
//        09-DEC-09 12:14:43
//        09-DEC-09 12:14:45
//    c2 ----done
//    c1 rollback
//    c1 ----selecting
//    c1 ----done
//    c2 ----selecting
//    c2 ----done
//    Dropped table
//    c1 is 
//    c2 is Resource id #5

?>

注释

Note:

An incorrectly installed or configured OCI8 extension will often manifest itself as a connection problem or error. See Installing/Configuring for troubleshooting information.

Note:

In PHP versions before 5.0.0 use ocilogon() instead. 在当前版本中,旧的函数名还可以被使用,但已经被废弃并不建议使用。

参见

User Contributed Notes

blake dot lewis at gmail dot com 08-Mar-2013 03:10
Using ldap for Oracle name resolution:

  The web server will need the environmental variable TNS_ADMIN='Directory of tnsname.ora' unless the default location is used. I use '/etc/tns_admin'. Confirm using the phpinfo().

  There are three files needed in the TNS_ADMIN location: tnsnames.ora, sqlnet.ora and ldap.ora. If you are only using ldap, tnsnames.ora is not needed.

  To sqlnet.ora add:
     NAMES.DIRECTORY_PATH=(TNSNAMES,LDAP)

  To ldap.ora add:
     DIRECTORY_SERVERS=(ldap_server_fqdn:port)
     DEFAULT_ADMIN_CONTEXT=""
     DIRECTORY_SERVER_TYPE=OID

  For a quick and dirty ldap tnsnames server use tnsManager by Dave Berry. Oracle OID or Openldap can used, but are complicated to setup. tnsManager is a no brainer. The quick part: give it a tnsnames.ora file and start it up. The dirty parts: I can't get Toad and SQLDeveloper to work with it, it ignores the domain and it is no longer being maintained.

  The order of values in NAMES.DIRECTORY_PATH in sqlnet.ora determines which look up 'adapter' is used, in this case it is tnsnames.ora file and then ldap. I use ldap for general consumption and tnsnames.ora file to override ldap or entries that are not for general consumption.

  If you have the full Oracle client you have tnsping. 'tnsping ORACLE_SID' will tell you what adapter you are using: 'Used LDAP adapter to resolve the alias'.

<?php
 
echo system("/PATH/tnsping ".$ORACLE_SID." 2>&1")."<br />";
  echo
'TNS_ADMIN='.getenv('TNS_ADMIN');
?>

ISSUE:
  If connecting with only ORACLE_SID and not ORACLE_SID.DB_DOMAIN, the value of NAMES.DEFAULT_DOMAIN from sqlnet.ora is appended, then for some reason PHP tries the HOSTNAME adapter, and if the database name resolves in DNS, it will fail connecting using the database name as the hostname, because neither SID nor SERVICE_NAME are defined.
  If using tnsManager append '.ANY_DOMAIN' to $ORACLE_SID to hack around the issue above.

  I have tested with:
       11.1.0.7 full client and PHP 5.1.6
       11.2.0.2 full client and PHP 5.4.11

  I have heard that LDAP lookup does not work with older instantclients.
blake dot lewis at gmail dot com 15-Feb-2013 11:38
Using ldap for Oracle name resolution:

  The web server needs the environmental variable TNS_ADMIN='Directory of tnsname.ora'. I use '/etc/tns_admin'. Confirm using the phpinfo() function.

  There are three files needed in the TNS_ADMIN location: tnsnames.ora, sqlnet.ora and ldap.ora. If you are only using ldap, tnsnames.ora is not needed.

  To sqlnet.ora add:
     NAMES.DIRECTORY_PATH=(TNSNAMES,LDAP)

  To ldap.ora add:
     DIRECTORY_SERVERS=(ldap_fqdn_hostname:1575)
     DEFAULT_ADMIN_CONTEXT=""
     DIRECTORY_SERVER_TYPE=OID

  For a quick and dirty ldap tnsnames server use tnsManager by Dave Berry. Oracle OID or Openldap can used, but are complicated to setup. tnsManager is a no brainer. The default port is 1575.

  The order of values in NAMES.DIRECTORY_PATH from sqlnet.ora determines which look up 'adapter' is used first, in this case it is tnsnames.ora file and then ldap. I use ldap for general consumption and tnsnames.ora file to override ldap or entries that are not for general consumption.

  If you have the full Oracle client you have tnsping. 'tnsping ORACLE_SID' will tell you what adapter you are using: 'Used LDAP adapter to resolve the alias'.

<?php
 
echo system("/PATH/tnsping ".$ORACLE_SID." 2>&1")."<br />";
  echo
'TNS_ADMIN='.getenv('TNS_ADMIN');
?>

ISSUE:
  For some reason PHP tries the HOSTNAME adapter first, and if the database name resolves in DNS, it will try connecting using the database name as the hostname with no SID or SERVICE_NAME defined. All other Oracle clients I have used will not try the HOSTNAME adapter unless it is listed in NAMES.DIRECTORY_PATH.
  I have heard that LDAP look up does not work with older instantclients.
Anonymous 10-Feb-2012 06:33
How to connect from PHP to an Oracle database using OID (Oracle Internet Directory):

OID is like a lookup index that contains connection strings for connecting to various databases. Without OID, a database connection string would be stored directly in the code settings and used by the PHP code to connect to a database. With OID, a lookup can be made to the OID LDAP to acquire the database connection string. Then the PHP code will use the acquired database connection string to connect to the database as before.

OID allows a DBA to manage/change which database server that an application uses without having to change any database settings in the PHP application itself or on the application server.

Here are the basic steps for PHP to connect to a database via OID:

- The DBA should provide you the connection information for the OID LDAP as well as the username/password for the database connection.
- Connect to the OID LDAP using the provided information
- Search for the appropriate LDAP record
- Get the connection string data from the record attribute, \&quot;orclnetdescstring\&quot;
- Close the LDAP connection
- Use the acquired connection string data to connect to the database as usual using the provided database username/password.

Here is basic sample code to do this:

// Get connection string from OID LDAP

    $ds=ldap_connect($servername,$serverport); // Connect to ldap
    $r=ldap_bind($ds); // Bind to ldap
    $sr = ldap_search($ds, \&quot;cn=OracleContext,dc=___,dc=___,dc=___\&quot;, \&quot;cn=$sid\&quot;); // Run query
    $info = ldap_get_entries($ds, $sr); // Get entries
    ldap_close($ds); // Close connection

    $dbconnectstring = $info[0][\&quot;orclnetdescstring\&quot;][0]; // Extract db connect string from ldap search result array

// Connect to database using acquired connection string from OID

    $dbconnection = oci_connect ($username,$password,$dbconnectstring);
peter at goldthorp dot com 07-Aug-2011 03:28
I started getting "ORA-12514: TNS:listener does not currently know of service requested in connect descriptor" errors when I upgraded my database instance from 10.2 to 11.2.  For some reason it would not resolve the oci_connect calls with the Easy Connect syntax (easy connect calls from sqlplus were fine).  I was able to workaround the issue by passing a tns connect string:

<?php
$db
= "(DESCRIPTION=(ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.XX.XXX)(PORT = 1521)))(CONNECT_DATA=(SID=XXXX)))";

$c1 = oci_connect("name","password",$db);
?>
jtacon at php dot net 07-Feb-2011 05:24
If you upgrades the OCI8, be sure to use the latest oracle instantclient version, otherwise you can receive an "ORA-24315: illegal attribute type" when trying to connect due to incompatibility with some versions.

HTH,
Javier Tacón
Jonathon Robinson 15-Jun-2010 11:12
Regarding the following statement in the documentation:
"The second and subsequent calls to oci_connect() with the same parameters will return the connection handle returned from the first call."

There's one caveat here.  Subsequent calls to oci_connect() will only return the same connection handle as the first call as long as a reference is held to the original handle.

For example, the following code will generate *one* connection handle:

<?php
$dbh
= oci_connect($username, $password, $conn_info);
// Do stuff
$dbh = oci_connect$username, $password, $conn_info);
// Do more stuff

The follow code will generate *two* connection handles:
getData();
// Do stuff
getData();
// Do more stuff

getData() {
   
$dbh = oci_connect($username, $password, $conn_info);
   
// Do stuff
}
?>

This is the result of PHP garbage collecting the handle at the end of the method scope.

If you want to isolate your DB layer through function calls but still want to leverage the fact that oci_connect can return the same handle, just keep a reference to the handle like so:

<?php
getData
($username, $password, $conn_info) {
   
$dbh = oci_connect($username, $password, $conn_info);
   
$key = hash('md5', "$username|$password|$conn_info");
   
$GLOBALS[$key] = $dbh;
   
// Do stuff
}
?>

I originally logged this as a bug but apparently this is the expected behaviour, likely because oci_close($dbh) just calls unset($dbh).
drew dot carmichael at gmail dot com 03-Jul-2009 01:55
When using the OCI_CRED_EXT in php
if the ENV $ORACLE_SID is set the DB does not need to be specified explicitly and the connection will fail unless you provide a NULL DB value when creating the connection.

The $ORACLE_SID trumps the TNS name look up for the connection. So even a manual connection string in the DB parameter will fail.

So when the $ORACLE_SID Env is set a NULL passed instead of the DB name connects successfully.

Hope this saves some hair pulling when moving to %.3 and OS Authentications
Leandro da Cunha Campos 11-May-2009 11:04
ONE ALTERNATIVE OF CONNECT IN ORACLE RAC "Real Application Clusters"

<?php
$dbstr
="(DESCRIPTION =(ADDRESS = (PROTOCOL = TCP)(HOST =ip1)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = banco)
(INSTANCE_NAME = banco1)))"
;
 
$dbstr1 ="(DESCRIPTION =(ADDRESS = (PROTOCOL = TCP)(HOST =ip2)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = banco)
(INSTANCE_NAME = banco2)))"
;
 
if(!@(
$conn = oci_connect('user','password',$dbstr1)))
{
$conn = oci_connect('user','password',$dbstr) or die (ocierror()); }
?>
sixd at php dot net 30-Jun-2008 04:33
If you want to specify a connection timeout in case there is network problem, you can edit the client side (e.g. PHP side) sqlnet.ora file and set SQLNET.OUTBOUND_CONNECT_TIMEOUT. This sets the upper time limit for establishing a connection right through to the DB, including the time for attempts to connect to other services.   It is available from Oracle 10.2.0.3 onwards.

In Oracle 11.1, a slightly lighter-weight solution TCP.CONNECT_TIMEOUT was introduced.  It also is a sqlnet.ora parameter.  It bounds just the TCP connection establishment time, which is mostly where connection problem are seen.

The client sqlnet.ora file should be put in the same directory as the tnsnames.ora file.
sebastien.barbieri _at_ gmail dot com 13-Sep-2006 09:42
When you are using Oracle 9.2+ I would say that you MUST use the CHARSET parameter.

Of course, you will not notice it until there is accented character... so just specify it and you will avoid a big headache.

So for example here is our Oracle internal conf:
select * from nls_database_parameters;
 
PARAMETER                      VALUE
------------------------------ ----------------------------------------
...
NLS_LANGUAGE                   AMERICAN
NLS_TERRITORY                  AMERICA
NLS_ISO_CURRENCY               AMERICA
NLS_CHARACTERSET               WE8ISO8859P15
...
 
And there our oci_connect call:

$dbch=ocilogon($user,$pass,$connectString,"WE8ISO8859P15");

Without that, you will get question mark (inversed), squares... instead of most accented character.

Don't forget to use that for writing as well as for reading.
ben at onshop dot co dot uk 14-Jul-2005 05:25
There is a useful solution to the problem of securing connection information in the PHP Cookbook (O'Reilly) by David Sklar and Adam Trachtenberg. They propose using 'SetEnv' in the Apache configuration and then accessing the values from within a script using $_SERVER.

Unfortunately using the 'SetEnv' solution exposes your connection information to all users of that virtual host. If they run phpinfo.php or display $_SERVER, I found that they will see the password from any file under the root of that virtual host.

To restrict exposure to a particular directory or specific file:

1. First put an 'Include' to the secret file in httpd.conf. For example:

Include "/web/private/secret.txt"

2. In the password file, use the 'SetEnvIf' directive to enable the Environment variables by directory only or within a specific file. For example:

- For all files in the directory:

SetEnvIf Request_URI "/path/to/my/directory" ORACLE_PASS=5gHj790j

- For a specific file in the directory

SetEnvIf Request_URI "/path/to/my/directory/connection.oracle.php" ORACLE_PASS=5gHj790j
M0no at ethonfusino dot com 21-Nov-2002 10:04
If your oracle database is on a remote system within your local network and you don't want to worry about the tnsnames file you can try this.

$db = "(DESCRIPTION=(ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.XX.XXX)(PORT = 1521)))(CONNECT_DATA=(SID=XXXX)))";

$c1 = ocilogon("name","password",$db);

Hope this helps someone.