Introduction

These functions allow you to access Oracle 10, Oracle 9, Oracle 8 and Oracle 7 databases using the Oracle Call Interface (OCI). They support binding of PHP variables to Oracle placeholders, have full LOB, FILE and ROWID support, and allow you to use user-supplied define variables.

Requirements

You will need the Oracle client libraries to use this extension. Windows users will need at least Oracle version 8.1 to use the php_oci8.dll dll.

The most convenient way to install all the required files is to use Oracle Instant Client, which is available from here: http://www.oracle.com/technology/tech/oci/instantclient/instantclient.html. Instant Client does not need ORACLE_SID or ORACLE_HOME environment variables set. You still may need to set LD_LIBRARY_PATH and NLS_LANG, though.

Before using this extension, make sure that you have set up your Oracle environment variables properly for the Oracle user, as well as your web daemon user. These variables should be set up before you start your web-server. The variables you might need to set are as follows:

• ORACLE_HOME

• ORACLE_SID

• LD_PRELOAD

• LD_LIBRARY_PATH

• NLS_LANG

After setting up the environment variables for your webserver user, be sure to also add the webserver user (nobody, www) to the oracle group.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Here's a short explanation of the configuration directives.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

Examples

Example 1. Basic query <?php   $conn = oci_connect('hr', 'hr', 'orcl');   if (!$conn) {     $e = oci_error();     print htmlentities($e['message']);     exit;   }   $query = 'SELECT * FROM DEPARTMENTS';   $stid = oci_parse($conn, $query);   if (!$stid) {     $e = oci_error($conn);     print htmlentities($e['message']);     exit;   }   $r = oci_execute($stid, OCI_DEFAULT);   if (!$r) {     $e = oci_error($stid);     echo htmlentities($e['message']);     exit;   }   print '<table border="1">';   while ($row = oci_fetch_array($stid, OCI_RETURN_NULLS)) {     print '<tr>';        foreach ($row as $item) {          print '<td>'.($item?htmlentities($item):'&nbsp;').'</td>';        }        print '</tr>';   }   print '</table>';   oci_close($conn); ?>

Example 2. Insert with bind variables <?php   // Before running, create the table:   //   CREATE TABLE MYTABLE (mid NUMBER, myd VARCHAR2(20));   $conn = oci_connect('scott', 'tiger', 'orcl');   $query = 'INSERT INTO MYTABLE VALUES(:myid, :mydata)';   $stid = oci_parse($conn, $query);   $id = 60;   $data = 'Some data';   oci_bind_by_name($stid, ':myid', $id);   oci_bind_by_name($stid, ':mydata', $data);   $r = oci_execute($stid);   if ($r)     print "One row inserted";   oci_close($conn); ?>

Example 3. Inserting data into a CLOB column <?php // Before running, create the table: //     CREATE TABLE MYTABLE (mykey NUMBER, myclob CLOB); $conn = oci_connect('scott', 'tiger', 'orcl'); $mykey = 12343;  // arbitrary key for this example; $sql = "INSERT INTO mytable (mykey, myclob)         VALUES (:mykey, EMPTY_CLOB())         RETURNING myclob INTO :myclob"; $stid = oci_parse($conn, $sql); $clob = oci_new_descriptor($conn, OCI_D_LOB); oci_bind_by_name($stid, ":mykey", $mykey, 5); oci_bind_by_name($stid, ":myclob", $clob, -1, OCI_B_CLOB); oci_execute($stid, OCI_DEFAULT); $clob->save("A very long string"); oci_commit($conn); // Fetching CLOB data $query = 'SELECT myclob FROM mytable WHERE mykey = :mykey'; $stid = oci_parse ($conn, $query); oci_bind_by_name($stid, ":mykey", $mykey, 5); oci_execute($stid, OCI_DEFAULT); print '<table border="1">'; while ($row = oci_fetch_array($stid, OCI_ASSOC)) {   $result = $row['MYCLOB']->load();   print '<tr><td>'.$result.'</td></tr>'; } print '</table>'; ?>

You can easily access stored procedures in the same way as you would from the command line.

Example 4. Using Stored Procedures <?php // by webmaster at remoterealty dot com $sth = oci_parse($dbh, "begin sp_newaddress( :address_id, '$firstname', '$lastname', '$company', '$address1', '$address2', '$city', '$state', '$postalcode', '$country', :error_code );end;"); // This calls stored procedure sp_newaddress, with :address_id being an // in/out variable and :error_code being an out variable. // Then you do the binding:    oci_bind_by_name($sth, ":address_id", $addr_id, 10);    oci_bind_by_name($sth, ":error_code", $errorcode, 10);    oci_execute($sth); ?>

Connecting Handling

The oci8 extension provides you with 3 different functions for connecting to Oracle. It is up to you to use the most appropriate function for your application, and the information in this section is intended to help you make an informed choice.

Connecting to an Oracle server is a reasonably expensive operation, in terms of the time that it takes to complete. The oci_pconnect() function uses a persistent cache of connections that can be re-used across different script requests. This means that you will typically only incur the connection overhead once per php process (or apache child).

If your application connects to Oracle using a different set of credentials for each web user, the persistent cache employed by oci_pconnect() will become less useful as the number of concurrent users increases, to the point where it may start to adversely affect the overall performance of your Oracle server due to maintaining too many idle connections. If your application is structured in this way, it is recommended that you either tune your application using the oci8.max_persistent and oci8.persistent_timeout configuration settings (these will give you control over the persistent connection cache size and lifetime) or use oci_connect() instead.

Both oci_connect() and oci_pconnect() employ a connection cache; if you make multiple calls to oci_connect(), using the same parameters, in a given script, the second and subsequent calls return the existing connection handle. The cache used by oci_connect() is cleaned up at the end of the script run, or when you explicitly close the connection handle. oci_pconnect() has similar behaviour, although its cache is maintained separately and survives between requests.

This caching feature is important to remember, because it gives the appearance that the two handles are not transactionally isolated (they are in fact the same connection handle, so there is no isolation of any kind). If your application needs two separate, transactionally isolated connections, you should use oci_new_connect().

oci_new_connect() always creates a new connection to the Oracle server, regardless of what other connections might already exist. High traffic web applications should try to avoid using oci_new_connect(), especially in the busiest sections of the application.

Datatypes supported by the driver