Added PEAR:DB support plus database replication support

1 files changed, 1117 insertions, 0 deletions

diff --git a/program/lib/DB/oci8.php b/program/lib/DB/oci8.php
new file mode 100644
index 000000000..c610a04e8
--- /dev/null
+++ b/program/lib/DB/oci8.php
@@ -0,0 +1,1117 @@
+<?php
+
+/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
+
+/**
+ * The PEAR DB driver for PHP's oci8 extension
+ * for interacting with Oracle databases
+ *
+ * PHP versions 4 and 5
+ *
+ * LICENSE: This source file is subject to version 3.0 of the PHP license
+ * that is available through the world-wide-web at the following URI:
+ * http://www.php.net/license/3_0.txt.  If you did not receive a copy of
+ * the PHP License and are unable to obtain it through the web, please
+ * send a note to license@php.net so we can mail you a copy immediately.
+ *
+ * @category   Database
+ * @package    DB
+ * @author     James L. Pine <jlp@valinux.com>
+ * @author     Daniel Convissor <danielc@php.net>
+ * @copyright  1997-2005 The PHP Group
+ * @license    http://www.php.net/license/3_0.txt  PHP License 3.0
+ * @version    CVS: $Id$
+ * @link       http://pear.php.net/package/DB
+ */
+
+/**
+ * Obtain the DB_common class so it can be extended from
+ */
+require_once 'DB/common.php';
+
+/**
+ * The methods PEAR DB uses to interact with PHP's oci8 extension
+ * for interacting with Oracle databases
+ *
+ * Definitely works with versions 8 and 9 of Oracle.
+ *
+ * These methods overload the ones declared in DB_common.
+ *
+ * Be aware...  OCIError() only appears to return anything when given a
+ * statement, so functions return the generic DB_ERROR instead of more
+ * useful errors that have to do with feedback from the database.
+ *
+ * @category   Database
+ * @package    DB
+ * @author     James L. Pine <jlp@valinux.com>
+ * @author     Daniel Convissor <danielc@php.net>
+ * @copyright  1997-2005 The PHP Group
+ * @license    http://www.php.net/license/3_0.txt  PHP License 3.0
+ * @version    Release: @package_version@
+ * @link       http://pear.php.net/package/DB
+ */
+class DB_oci8 extends DB_common
+{
+    // {{{ properties
+
+    /**
+     * The DB driver type (mysql, oci8, odbc, etc.)
+     * @var string
+     */
+    var $phptype = 'oci8';
+
+    /**
+     * The database syntax variant to be used (db2, access, etc.), if any
+     * @var string
+     */
+    var $dbsyntax = 'oci8';
+
+    /**
+     * The capabilities of this DB implementation
+     *
+     * The 'new_link' element contains the PHP version that first provided
+     * new_link support for this DBMS.  Contains false if it's unsupported.
+     *
+     * Meaning of the 'limit' element:
+     *   + 'emulate' = emulate with fetch row by number
+     *   + 'alter'   = alter the query
+     *   + false     = skip rows
+     *
+     * @var array
+     */
+    var $features = array(
+        'limit'         => 'alter',
+        'new_link'      => '5.0.0',
+        'numrows'       => 'subquery',
+        'pconnect'      => true,
+        'prepare'       => true,
+        'ssl'           => false,
+        'transactions'  => true,
+    );
+
+    /**
+     * A mapping of native error codes to DB error codes
+     * @var array
+     */
+    var $errorcode_map = array(
+        1    => DB_ERROR_CONSTRAINT,
+        900  => DB_ERROR_SYNTAX,
+        904  => DB_ERROR_NOSUCHFIELD,
+        913  => DB_ERROR_VALUE_COUNT_ON_ROW,
+        921  => DB_ERROR_SYNTAX,
+        923  => DB_ERROR_SYNTAX,
+        942  => DB_ERROR_NOSUCHTABLE,
+        955  => DB_ERROR_ALREADY_EXISTS,
+        1400 => DB_ERROR_CONSTRAINT_NOT_NULL,
+        1401 => DB_ERROR_INVALID,
+        1407 => DB_ERROR_CONSTRAINT_NOT_NULL,
+        1418 => DB_ERROR_NOT_FOUND,
+        1476 => DB_ERROR_DIVZERO,
+        1722 => DB_ERROR_INVALID_NUMBER,
+        2289 => DB_ERROR_NOSUCHTABLE,
+        2291 => DB_ERROR_CONSTRAINT,
+        2292 => DB_ERROR_CONSTRAINT,
+        2449 => DB_ERROR_CONSTRAINT,
+    );
+
+    /**
+     * The raw database connection created by PHP
+     * @var resource
+     */
+    var $connection;
+
+    /**
+     * The DSN information for connecting to a database
+     * @var array
+     */
+    var $dsn = array();
+
+
+    /**
+     * Should data manipulation queries be committed automatically?
+     * @var bool
+     * @access private
+     */
+    var $autocommit = true;
+
+    /**
+     * Stores the $data passed to execute() in the oci8 driver
+     *
+     * Gets reset to array() when simpleQuery() is run.
+     *
+     * Needed in case user wants to call numRows() after prepare/execute
+     * was used.
+     *
+     * @var array
+     * @access private
+     */
+    var $_data = array();
+
+    /**
+     * The result or statement handle from the most recently executed query
+     * @var resource
+     */
+    var $last_stmt;
+
+    /**
+     * Is the given prepared statement a data manipulation query?
+     * @var array
+     * @access private
+     */
+    var $manip_query = array();
+
+
+    // }}}
+    // {{{ constructor
+
+    /**
+     * This constructor calls <kbd>$this->DB_common()</kbd>
+     *
+     * @return void
+     */
+    function DB_oci8()
+    {
+        $this->DB_common();
+    }
+
+    // }}}
+    // {{{ connect()
+
+    /**
+     * Connect to the database server, log in and open the database
+     *
+     * Don't call this method directly.  Use DB::connect() instead.
+     *
+     * If PHP is at version 5.0.0 or greater:
+     *   + Generally, oci_connect() or oci_pconnect() are used.
+     *   + But if the new_link DSN option is set to true, oci_new_connect()
+     *     is used.
+     *
+     * When using PHP version 4.x, OCILogon() or OCIPLogon() are used.
+     *
+     * PEAR DB's oci8 driver supports the following extra DSN options:
+     *   + charset       The character set to be used on the connection.
+     *                    Only used if PHP is at version 5.0.0 or greater
+     *                    and the Oracle server is at 9.2 or greater.
+     *                    Available since PEAR DB 1.7.0.
+     *   + new_link      If set to true, causes subsequent calls to
+     *                    connect() to return a new connection link
+     *                    instead of the existing one.  WARNING: this is
+     *                    not portable to other DBMS's.
+     *                    Available since PEAR DB 1.7.0.
+     *
+     * @param array $dsn         the data source name
+     * @param bool  $persistent  should the connection be persistent?
+     *
+     * @return int  DB_OK on success. A DB_Error object on failure.
+     */
+    function connect($dsn, $persistent = false)
+    {
+        if (!PEAR::loadExtension('oci8')) {
+            return $this->raiseError(DB_ERROR_EXTENSION_NOT_FOUND);
+        }
+
+        $this->dsn = $dsn;
+        if ($dsn['dbsyntax']) {
+            $this->dbsyntax = $dsn['dbsyntax'];
+        }
+
+        if (function_exists('oci_connect')) {
+            if (isset($dsn['new_link'])
+                && ($dsn['new_link'] == 'true' || $dsn['new_link'] === true))
+            {
+                $connect_function = 'oci_new_connect';
+            } else {
+                $connect_function = $persistent ? 'oci_pconnect'
+                                    : 'oci_connect';
+            }
+
+            // Backwards compatibility with DB < 1.7.0
+            if (empty($dsn['database']) && !empty($dsn['hostspec'])) {
+                $db = $dsn['hostspec'];
+            } else {
+                $db = $dsn['database'];
+            }
+
+            $char = empty($dsn['charset']) ? null : $dsn['charset'];
+            $this->connection = @$connect_function($dsn['username'],
+                                                   $dsn['password'],
+                                                   $db,
+                                                   $char);
+            $error = OCIError();
+            if (!empty($error) && $error['code'] == 12541) {
+                // Couldn't find TNS listener.  Try direct connection.
+                $this->connection = @$connect_function($dsn['username'],
+                                                       $dsn['password'],
+                                                       null,
+                                                       $char);
+            }
+        } else {
+            $connect_function = $persistent ? 'OCIPLogon' : 'OCILogon';
+            if ($dsn['hostspec']) {
+                $this->connection = @$connect_function($dsn['username'],
+                                                       $dsn['password'],
+                                                       $dsn['hostspec']);
+            } elseif ($dsn['username'] || $dsn['password']) {
+                $this->connection = @$connect_function($dsn['username'],
+                                                       $dsn['password']);
+            }
+        }
+
+        if (!$this->connection) {
+            $error = OCIError();
+            $error = (is_array($error)) ? $error['message'] : null;
+            return $this->raiseError(DB_ERROR_CONNECT_FAILED,
+                                     null, null, null,
+                                     $error);
+        }
+        return DB_OK;
+    }
+
+    // }}}
+    // {{{ disconnect()
+
+    /**
+     * Disconnects from the database server
+     *
+     * @return bool  TRUE on success, FALSE on failure
+     */
+    function disconnect()
+    {
+        if (function_exists('oci_close')) {
+            $ret = @oci_close($this->connection);
+        } else {
+            $ret = @OCILogOff($this->connection);
+        }
+        $this->connection = null;
+        return $ret;
+    }
+
+    // }}}
+    // {{{ simpleQuery()
+
+    /**
+     * Sends a query to the database server
+     *
+     * To determine how many rows of a result set get buffered using
+     * ocisetprefetch(), see the "result_buffering" option in setOptions().
+     * This option was added in Release 1.7.0.
+     *
+     * @param string  the SQL query string
+     *
+     * @return mixed  + a PHP result resrouce for successful SELECT queries
+     *                + the DB_OK constant for other successful queries
+     *                + a DB_Error object on failure
+     */
+    function simpleQuery($query)
+    {
+        $this->_data = array();
+        $this->last_parameters = array();
+        $this->last_query = $query;
+        $query = $this->modifyQuery($query);
+        $result = @OCIParse($this->connection, $query);
+        if (!$result) {
+            return $this->oci8RaiseError();
+        }
+        if ($this->autocommit) {
+            $success = @OCIExecute($result,OCI_COMMIT_ON_SUCCESS);
+        } else {
+            $success = @OCIExecute($result,OCI_DEFAULT);
+        }
+        if (!$success) {
+            return $this->oci8RaiseError($result);
+        }
+        $this->last_stmt = $result;
+        if (DB::isManip($query)) {
+            return DB_OK;
+        } else {
+            @ocisetprefetch($result, $this->options['result_buffering']);
+            return $result;
+        }
+    }
+
+    // }}}
+    // {{{ nextResult()
+
+    /**
+     * Move the internal oracle result pointer to the next available result
+     *
+     * @param a valid oci8 result resource
+     *
+     * @access public
+     *
+     * @return true if a result is available otherwise return false
+     */
+    function nextResult($result)
+    {
+        return false;
+    }
+
+    // }}}
+    // {{{ fetchInto()
+
+    /**
+     * Places a row from the result set into the given array
+     *
+     * Formating of the array and the data therein are configurable.
+     * See DB_result::fetchInto() for more information.
+     *
+     * This method is not meant to be called directly.  Use
+     * DB_result::fetchInto() instead.  It can't be declared "protected"
+     * because DB_result is a separate object.
+     *
+     * @param resource $result    the query result resource
+     * @param array    $arr       the referenced array to put the data in
+     * @param int      $fetchmode how the resulting array should be indexed
+     * @param int      $rownum    the row number to fetch (0 = first row)
+     *
+     * @return mixed  DB_OK on success, NULL when the end of a result set is
+     *                 reached or on failure
+     *
+     * @see DB_result::fetchInto()
+     */
+    function fetchInto($result, &$arr, $fetchmode, $rownum = null)
+    {
+        if ($rownum !== null) {
+            return $this->raiseError(DB_ERROR_NOT_CAPABLE);
+        }
+        if ($fetchmode & DB_FETCHMODE_ASSOC) {
+            $moredata = @OCIFetchInto($result,$arr,OCI_ASSOC+OCI_RETURN_NULLS+OCI_RETURN_LOBS);
+            if ($this->options['portability'] & DB_PORTABILITY_LOWERCASE &&
+                $moredata)
+            {
+                $arr = array_change_key_case($arr, CASE_LOWER);
+            }
+        } else {
+            $moredata = OCIFetchInto($result,$arr,OCI_RETURN_NULLS+OCI_RETURN_LOBS);
+        }
+        if (!$moredata) {
+            return null;
+        }
+        if ($this->options['portability'] & DB_PORTABILITY_RTRIM) {
+            $this->_rtrimArrayValues($arr);
+        }
+        if ($this->options['portability'] & DB_PORTABILITY_NULL_TO_EMPTY) {
+            $this->_convertNullArrayValuesToEmpty($arr);
+        }
+        return DB_OK;
+    }
+
+    // }}}
+    // {{{ freeResult()
+
+    /**
+     * Deletes the result set and frees the memory occupied by the result set
+     *
+     * This method is not meant to be called directly.  Use
+     * DB_result::free() instead.  It can't be declared "protected"
+     * because DB_result is a separate object.
+     *
+     * @param resource $result  PHP's query result resource
+     *
+     * @return bool  TRUE on success, FALSE if $result is invalid
+     *
+     * @see DB_result::free()
+     */
+    function freeResult($result)
+    {
+        return @OCIFreeStatement($result);
+    }
+
+    /**
+     * Frees the internal resources associated with a prepared query
+     *
+     * @param resource $stmt           the prepared statement's resource
+     * @param bool     $free_resource  should the PHP resource be freed too?
+     *                                  Use false if you need to get data
+     *                                  from the result set later.
+     *
+     * @return bool  TRUE on success, FALSE if $result is invalid
+     *
+     * @see DB_oci8::prepare()
+     */
+    function freePrepared($stmt, $free_resource = true)
+    {
+        if (!is_resource($stmt)) {
+            return false;
+        }
+        if ($free_resource) {
+            @ocifreestatement($stmt);
+        }
+        if (isset($this->prepare_types[(int)$stmt])) {
+            unset($this->prepare_types[(int)$stmt]);
+            unset($this->manip_query[(int)$stmt]);
+        } else {
+            return false;
+        }
+        return true;
+    }
+
+    // }}}
+    // {{{ numRows()
+
+    /**
+     * Gets the number of rows in a result set
+     *
+     * Only works if the DB_PORTABILITY_NUMROWS portability option
+     * is turned on.
+     *
+     * This method is not meant to be called directly.  Use
+     * DB_result::numRows() instead.  It can't be declared "protected"
+     * because DB_result is a separate object.
+     *
+     * @param resource $result  PHP's query result resource
+     *
+     * @return int  the number of rows.  A DB_Error object on failure.
+     *
+     * @see DB_result::numRows(), DB_common::setOption()
+     */
+    function numRows($result)
+    {
+        // emulate numRows for Oracle.  yuck.
+        if ($this->options['portability'] & DB_PORTABILITY_NUMROWS &&
+            $result === $this->last_stmt)
+        {
+            $countquery = 'SELECT COUNT(*) FROM ('.$this->last_query.')';
+            $save_query = $this->last_query;
+            $save_stmt = $this->last_stmt;
+
+            if (count($this->_data)) {
+                $smt = $this->prepare('SELECT COUNT(*) FROM ('.$this->last_query.')');
+                $count = $this->execute($smt, $this->_data);
+            } else {
+                $count =& $this->query($countquery);
+            }
+
+            if (DB::isError($count) ||
+                DB::isError($row = $count->fetchRow(DB_FETCHMODE_ORDERED)))
+            {
+                $this->last_query = $save_query;
+                $this->last_stmt = $save_stmt;
+                return $this->raiseError(DB_ERROR_NOT_CAPABLE);
+            }
+            return $row[0];
+        }
+        return $this->raiseError(DB_ERROR_NOT_CAPABLE);
+    }
+
+    // }}}
+    // {{{ numCols()
+
+    /**
+     * Gets the number of columns in a result set
+     *
+     * This method is not meant to be called directly.  Use
+     * DB_result::numCols() instead.  It can't be declared "protected"
+     * because DB_result is a separate object.
+     *
+     * @param resource $result  PHP's query result resource
+     *
+     * @return int  the number of columns.  A DB_Error object on failure.
+     *
+     * @see DB_result::numCols()
+     */
+    function numCols($result)
+    {
+        $cols = @OCINumCols($result);
+        if (!$cols) {
+            return $this->oci8RaiseError($result);
+        }
+        return $cols;
+    }
+
+    // }}}
+    // {{{ prepare()
+
+    /**
+     * Prepares a query for multiple execution with execute().
+     *
+     * With oci8, this is emulated.
+     *
+     * prepare() requires a generic query as string like <code>
+     *    INSERT INTO numbers VALUES (?, ?, ?)
+     * </code>.  The <kbd>?</kbd> characters are placeholders.
+     *
+     * Three types of placeholders can be used:
+     *   + <kbd>?</kbd>  a quoted scalar value, i.e. strings, integers
+     *   + <kbd>!</kbd>  value is inserted 'as is'
+     *   + <kbd>&</kbd>  requires a file name.  The file's contents get
+     *                     inserted into the query (i.e. saving binary
+     *                     data in a db)
+     *
+     * Use backslashes to escape placeholder characters if you don't want
+     * them to be interpreted as placeholders.  Example: <code>
+     *    "UPDATE foo SET col=? WHERE col='over \& under'"
+     * </code>
+     *
+     * @param string $query  the query to be prepared
+     *
+     * @return mixed  DB statement resource on success. DB_Error on failure.
+     *
+     * @see DB_oci8::execute()
+     */
+    function prepare($query)
+    {
+        $tokens   = preg_split('/((?<!\\\)[&?!])/', $query, -1,
+                               PREG_SPLIT_DELIM_CAPTURE);
+        $binds    = count($tokens) - 1;
+        $token    = 0;
+        $types    = array();
+        $newquery = '';
+
+        foreach ($tokens as $key => $val) {
+            switch ($val) {
+                case '?':
+                    $types[$token++] = DB_PARAM_SCALAR;
+                    unset($tokens[$key]);
+                    break;
+                case '&':
+                    $types[$token++] = DB_PARAM_OPAQUE;
+                    unset($tokens[$key]);
+                    break;
+                case '!':
+                    $types[$token++] = DB_PARAM_MISC;
+                    unset($tokens[$key]);
+                    break;
+                default:
+                    $tokens[$key] = preg_replace('/\\\([&?!])/', "\\1", $val);
+                    if ($key != $binds) {
+                        $newquery .= $tokens[$key] . ':bind' . $token;
+                    } else {
+                        $newquery .= $tokens[$key];
+                    }
+            }
+        }
+
+        $this->last_query = $query;
+        $newquery = $this->modifyQuery($newquery);
+        if (!$stmt = @OCIParse($this->connection, $newquery)) {
+            return $this->oci8RaiseError();
+        }
+        $this->prepare_types[(int)$stmt] = $types;
+        $this->manip_query[(int)$stmt] = DB::isManip($query);
+        return $stmt;
+    }
+
+    // }}}
+    // {{{ execute()
+
+    /**
+     * Executes a DB statement prepared with prepare().
+     *
+     * To determine how many rows of a result set get buffered using
+     * ocisetprefetch(), see the "result_buffering" option in setOptions().
+     * This option was added in Release 1.7.0.
+     *
+     * @param resource  $stmt  a DB statement resource returned from prepare()
+     * @param mixed  $data  array, string or numeric data to be used in
+     *                      execution of the statement.  Quantity of items
+     *                      passed must match quantity of placeholders in
+     *                      query:  meaning 1 for non-array items or the
+     *                      quantity of elements in the array.
+     *
+     * @return mixed  returns an oic8 result resource for successful SELECT
+     *                queries, DB_OK for other successful queries.
+     *                A DB error object is returned on failure.
+     *
+     * @see DB_oci8::prepare()
+     */
+    function &execute($stmt, $data = array())
+    {
+        $data = (array)$data;
+        $this->last_parameters = $data;
+        $this->_data = $data;
+
+        $types =& $this->prepare_types[(int)$stmt];
+        if (count($types) != count($data)) {
+            $tmp =& $this->raiseError(DB_ERROR_MISMATCH);
+            return $tmp;
+        }
+
+        $i = 0;
+        foreach ($data as $key => $value) {
+            if ($types[$i] == DB_PARAM_MISC) {
+                /*
+                 * Oracle doesn't seem to have the ability to pass a
+                 * parameter along unchanged, so strip off quotes from start
+                 * and end, plus turn two single quotes to one single quote,
+                 * in order to avoid the quotes getting escaped by
+                 * Oracle and ending up in the database.
+                 */
+                $data[$key] = preg_replace("/^'(.*)'$/", "\\1", $data[$key]);
+                $data[$key] = str_replace("''", "'", $data[$key]);
+            } elseif ($types[$i] == DB_PARAM_OPAQUE) {
+                $fp = @fopen($data[$key], 'rb');
+                if (!$fp) {
+                    $tmp =& $this->raiseError(DB_ERROR_ACCESS_VIOLATION);
+                    return $tmp;
+                }
+                $data[$key] = fread($fp, filesize($data[$key]));
+                fclose($fp);
+            }
+            if (!@OCIBindByName($stmt, ':bind' . $i, $data[$key], -1)) {
+                $tmp = $this->oci8RaiseError($stmt);
+                return $tmp;
+            }
+            $i++;
+        }
+        if ($this->autocommit) {
+            $success = @OCIExecute($stmt, OCI_COMMIT_ON_SUCCESS);
+        } else {
+            $success = @OCIExecute($stmt, OCI_DEFAULT);
+        }
+        if (!$success) {
+            $tmp = $this->oci8RaiseError($stmt);
+            return $tmp;
+        }
+        $this->last_stmt = $stmt;
+        if ($this->manip_query[(int)$stmt]) {
+            $tmp = DB_OK;
+        } else {
+            @ocisetprefetch($stmt, $this->options['result_buffering']);
+            $tmp =& new DB_result($this, $stmt);
+        }
+        return $tmp;
+    }
+
+    // }}}
+    // {{{ autoCommit()
+
+    /**
+     * Enables or disables automatic commits
+     *
+     * @param bool $onoff  true turns it on, false turns it off
+     *
+     * @return int  DB_OK on success.  A DB_Error object if the driver
+     *               doesn't support auto-committing transactions.
+     */
+    function autoCommit($onoff = false)
+    {
+        $this->autocommit = (bool)$onoff;;
+        return DB_OK;
+    }
+
+    // }}}
+    // {{{ commit()
+
+    /**
+     * Commits the current transaction
+     *
+     * @return int  DB_OK on success.  A DB_Error object on failure.
+     */
+    function commit()
+    {
+        $result = @OCICommit($this->connection);
+        if (!$result) {
+            return $this->oci8RaiseError();
+        }
+        return DB_OK;
+    }
+
+    // }}}
+    // {{{ rollback()
+
+    /**
+     * Reverts the current transaction
+     *
+     * @return int  DB_OK on success.  A DB_Error object on failure.
+     */
+    function rollback()
+    {
+        $result = @OCIRollback($this->connection);
+        if (!$result) {
+            return $this->oci8RaiseError();
+        }
+        return DB_OK;
+    }
+
+    // }}}
+    // {{{ affectedRows()
+
+    /**
+     * Determines the number of rows affected by a data maniuplation query
+     *
+     * 0 is returned for queries that don't manipulate data.
+     *
+     * @return int  the number of rows.  A DB_Error object on failure.
+     */
+    function affectedRows()
+    {
+        if ($this->last_stmt === false) {
+            return $this->oci8RaiseError();
+        }
+        $result = @OCIRowCount($this->last_stmt);
+        if ($result === false) {
+            return $this->oci8RaiseError($this->last_stmt);
+        }
+        return $result;
+    }
+
+    // }}}
+    // {{{ modifyQuery()
+
+    /**
+     * Changes a query string for various DBMS specific reasons
+     *
+     * "SELECT 2+2" must be "SELECT 2+2 FROM dual" in Oracle.
+     *
+     * @param string $query  the query string to modify
+     *
+     * @return string  the modified query string
+     *
+     * @access protected
+     */
+    function modifyQuery($query)
+    {
+        if (preg_match('/^\s*SELECT/i', $query) &&
+            !preg_match('/\sFROM\s/i', $query)) {
+            $query .= ' FROM dual';
+        }
+        return $query;
+    }
+
+    // }}}
+    // {{{ modifyLimitQuery()
+
+    /**
+     * Adds LIMIT clauses to a query string according to current DBMS standards
+     *
+     * @param string $query   the query to modify
+     * @param int    $from    the row to start to fetching (0 = the first row)
+     * @param int    $count   the numbers of rows to fetch
+     * @param mixed  $params  array, string or numeric data to be used in
+     *                         execution of the statement.  Quantity of items
+     *                         passed must match quantity of placeholders in
+     *                         query:  meaning 1 placeholder for non-array
+     *                         parameters or 1 placeholder per array element.
+     *
+     * @return string  the query string with LIMIT clauses added
+     *
+     * @access protected
+     */
+    function modifyLimitQuery($query, $from, $count, $params = array())
+    {
+        // Let Oracle return the name of the columns instead of
+        // coding a "home" SQL parser
+
+        if (count($params)) {
+            $result = $this->prepare("SELECT * FROM ($query) "
+                                     . 'WHERE NULL = NULL');
+            $tmp =& $this->execute($result, $params);
+        } else {
+            $q_fields = "SELECT * FROM ($query) WHERE NULL = NULL";
+
+            if (!$result = @OCIParse($this->connection, $q_fields)) {
+                $this->last_query = $q_fields;
+                return $this->oci8RaiseError();
+            }
+            if (!@OCIExecute($result, OCI_DEFAULT)) {
+                $this->last_query = $q_fields;
+                return $this->oci8RaiseError($result);
+            }
+        }
+
+        $ncols = OCINumCols($result);
+        $cols  = array();
+        for ( $i = 1; $i <= $ncols; $i++ ) {
+            $cols[] = '"' . OCIColumnName($result, $i) . '"';
+        }
+        $fields = implode(', ', $cols);
+        // XXX Test that (tip by John Lim)
+        //if (preg_match('/^\s*SELECT\s+/is', $query, $match)) {
+        //    // Introduce the FIRST_ROWS Oracle query optimizer
+        //    $query = substr($query, strlen($match[0]), strlen($query));
+        //    $query = "SELECT /* +FIRST_ROWS */ " . $query;
+        //}
+
+        // Construct the query
+        // more at: http://marc.theaimsgroup.com/?l=php-db&m=99831958101212&w=2
+        // Perhaps this could be optimized with the use of Unions
+        $query = "SELECT $fields FROM".
+                 "  (SELECT rownum as linenum, $fields FROM".
+                 "      ($query)".
+                 '  WHERE rownum <= '. ($from + $count) .
+                 ') WHERE linenum >= ' . ++$from;
+        return $query;
+    }
+
+    // }}}
+    // {{{ nextId()
+
+    /**
+     * Returns the next free id in a sequence
+     *
+     * @param string  $seq_name  name of the sequence
+     * @param boolean $ondemand  when true, the seqence is automatically
+     *                            created if it does not exist
+     *
+     * @return int  the next id number in the sequence.
+     *               A DB_Error object on failure.
+     *
+     * @see DB_common::nextID(), DB_common::getSequenceName(),
+     *      DB_oci8::createSequence(), DB_oci8::dropSequence()
+     */
+    function nextId($seq_name, $ondemand = true)
+    {
+        $seqname = $this->getSequenceName($seq_name);
+        $repeat = 0;
+        do {
+            $this->expectError(DB_ERROR_NOSUCHTABLE);
+            $result =& $this->query("SELECT ${seqname}.nextval FROM dual");
+            $this->popExpect();
+            if ($ondemand && DB::isError($result) &&
+                $result->getCode() == DB_ERROR_NOSUCHTABLE) {
+                $repeat = 1;
+                $result = $this->createSequence($seq_name);
+                if (DB::isError($result)) {
+                    return $this->raiseError($result);
+                }
+            } else {
+                $repeat = 0;
+            }
+        } while ($repeat);
+        if (DB::isError($result)) {
+            return $this->raiseError($result);
+        }
+        $arr = $result->fetchRow(DB_FETCHMODE_ORDERED);
+        return $arr[0];
+    }
+
+    /**
+     * Creates a new sequence
+     *
+     * @param string $seq_name  name of the new sequence
+     *
+     * @return int  DB_OK on success.  A DB_Error object on failure.
+     *
+     * @see DB_common::createSequence(), DB_common::getSequenceName(),
+     *      DB_oci8::nextID(), DB_oci8::dropSequence()
+     */
+    function createSequence($seq_name)
+    {
+        return $this->query('CREATE SEQUENCE '
+                            . $this->getSequenceName($seq_name));
+    }
+
+    // }}}
+    // {{{ dropSequence()
+
+    /**
+     * Deletes a sequence
+     *
+     * @param string $seq_name  name of the sequence to be deleted
+     *
+     * @return int  DB_OK on success.  A DB_Error object on failure.
+     *
+     * @see DB_common::dropSequence(), DB_common::getSequenceName(),
+     *      DB_oci8::nextID(), DB_oci8::createSequence()
+     */
+    function dropSequence($seq_name)
+    {
+        return $this->query('DROP SEQUENCE '
+                            . $this->getSequenceName($seq_name));
+    }
+
+    // }}}
+    // {{{ oci8RaiseError()
+
+    /**
+     * Produces a DB_Error object regarding the current problem
+     *
+     * @param int $errno  if the error is being manually raised pass a
+     *                     DB_ERROR* constant here.  If this isn't passed
+     *                     the error information gathered from the DBMS.
+     *
+     * @return object  the DB_Error object
+     *
+     * @see DB_common::raiseError(),
+     *      DB_oci8::errorNative(), DB_oci8::errorCode()
+     */
+    function oci8RaiseError($errno = null)
+    {
+        if ($errno === null) {
+            $error = @OCIError($this->connection);
+            return $this->raiseError($this->errorCode($error['code']),
+                                     null, null, null, $error['message']);
+        } elseif (is_resource($errno)) {
+            $error = @OCIError($errno);
+            return $this->raiseError($this->errorCode($error['code']),
+                                     null, null, null, $error['message']);
+        }
+        return $this->raiseError($this->errorCode($errno));
+    }
+
+    // }}}
+    // {{{ errorNative()
+
+    /**
+     * Gets the DBMS' native error code produced by the last query
+     *
+     * @return int  the DBMS' error code.  FALSE if the code could not be
+     *               determined
+     */
+    function errorNative()
+    {
+        if (is_resource($this->last_stmt)) {
+            $error = @OCIError($this->last_stmt);
+        } else {
+            $error = @OCIError($this->connection);
+        }
+        if (is_array($error)) {
+            return $error['code'];
+        }
+        return false;
+    }
+
+    // }}}
+    // {{{ tableInfo()
+
+    /**
+     * Returns information about a table or a result set
+     *
+     * NOTE: only supports 'table' and 'flags' if <var>$result</var>
+     * is a table name.
+     *
+     * NOTE: flags won't contain index information.
+     *
+     * @param object|string  $result  DB_result object from a query or a
+     *                                 string containing the name of a table.
+     *                                 While this also accepts a query result
+     *                                 resource identifier, this behavior is
+     *                                 deprecated.
+     * @param int            $mode    a valid tableInfo mode
+     *
+     * @return array  an associative array with the information requested.
+     *                 A DB_Error object on failure.
+     *
+     * @see DB_common::tableInfo()
+     */
+    function tableInfo($result, $mode = null)
+    {
+        if ($this->options['portability'] & DB_PORTABILITY_LOWERCASE) {
+            $case_func = 'strtolower';
+        } else {
+            $case_func = 'strval';
+        }
+
+        $res = array();
+
+        if (is_string($result)) {
+            /*
+             * Probably received a table name.
+             * Create a result resource identifier.
+             */
+            $result = strtoupper($result);
+            $q_fields = 'SELECT column_name, data_type, data_length, '
+                        . 'nullable '
+                        . 'FROM user_tab_columns '
+                        . "WHERE table_name='$result' ORDER BY column_id";
+
+            $this->last_query = $q_fields;
+
+            if (!$stmt = @OCIParse($this->connection, $q_fields)) {
+                return $this->oci8RaiseError(DB_ERROR_NEED_MORE_DATA);
+            }
+            if (!@OCIExecute($stmt, OCI_DEFAULT)) {
+                return $this->oci8RaiseError($stmt);
+            }
+
+            $i = 0;
+            while (@OCIFetch($stmt)) {
+                $res[$i] = array(
+                    'table' => $case_func($result),
+                    'name'  => $case_func(@OCIResult($stmt, 1)),
+                    'type'  => @OCIResult($stmt, 2),
+                    'len'   => @OCIResult($stmt, 3),
+                    'flags' => (@OCIResult($stmt, 4) == 'N') ? 'not_null' : '',
+                );
+                if ($mode & DB_TABLEINFO_ORDER) {
+                    $res['order'][$res[$i]['name']] = $i;
+                }
+                if ($mode & DB_TABLEINFO_ORDERTABLE) {
+                    $res['ordertable'][$res[$i]['table']][$res[$i]['name']] = $i;
+                }
+                $i++;
+            }
+
+            if ($mode) {
+                $res['num_fields'] = $i;
+            }
+            @OCIFreeStatement($stmt);
+
+        } else {
+            if (isset($result->result)) {
+                /*
+                 * Probably received a result object.
+                 * Extract the result resource identifier.
+                 */
+                $result = $result->result;
+            }
+
+            $res = array();
+
+            if ($result === $this->last_stmt) {
+                $count = @OCINumCols($result);
+                if ($mode) {
+                    $res['num_fields'] = $count;
+                }
+                for ($i = 0; $i < $count; $i++) {
+                    $res[$i] = array(
+                        'table' => '',
+                        'name'  => $case_func(@OCIColumnName($result, $i+1)),
+                        'type'  => @OCIColumnType($result, $i+1),
+                        'len'   => @OCIColumnSize($result, $i+1),
+                        'flags' => '',
+                    );
+                    if ($mode & DB_TABLEINFO_ORDER) {
+                        $res['order'][$res[$i]['name']] = $i;
+                    }
+                    if ($mode & DB_TABLEINFO_ORDERTABLE) {
+                        $res['ordertable'][$res[$i]['table']][$res[$i]['name']] = $i;
+                    }
+                }
+            } else {
+                return $this->raiseError(DB_ERROR_NOT_CAPABLE);
+            }
+        }
+        return $res;
+    }
+
+    // }}}
+    // {{{ getSpecialQuery()
+
+    /**
+     * Obtains the query string needed for listing a given type of objects
+     *
+     * @param string $type  the kind of objects you want to retrieve
+     *
+     * @return string  the SQL query string or null if the driver doesn't
+     *                  support the object type requested
+     *
+     * @access protected
+     * @see DB_common::getListOf()
+     */
+    function getSpecialQuery($type)
+    {
+        switch ($type) {
+            case 'tables':
+                return 'SELECT table_name FROM user_tables';
+            case 'synonyms':
+                return 'SELECT synonym_name FROM user_synonyms';
+            default:
+                return null;
+        }
+    }
+
+    // }}}
+
+}
+
+/*
+ * Local variables:
+ * tab-width: 4
+ * c-basic-offset: 4
+ * End:
+ */
+
+?>