Start of the refactoring. Commit is quite big because I forgot to use git right from the beginning. Sorry.

4 files changed, 706 insertions, 0 deletions

diff --git a/3dparty/MDB2/Driver/Function/Common.php b/3dparty/MDB2/Driver/Function/Common.php
new file mode 100644
index 00000000000..731f06882ce
--- /dev/null
+++ b/3dparty/MDB2/Driver/Function/Common.php
@@ -0,0 +1,293 @@
+<?php
+// +----------------------------------------------------------------------+
+// | PHP versions 4 and 5                                                 |
+// +----------------------------------------------------------------------+
+// | Copyright (c) 1998-2006 Manuel Lemos, Tomas V.V.Cox,                 |
+// | Stig. S. Bakken, Lukas Smith                                         |
+// | All rights reserved.                                                 |
+// +----------------------------------------------------------------------+
+// | MDB2 is a merge of PEAR DB and Metabases that provides a unified DB  |
+// | API as well as database abstraction for PHP applications.            |
+// | This LICENSE is in the BSD license style.                            |
+// |                                                                      |
+// | Redistribution and use in source and binary forms, with or without   |
+// | modification, are permitted provided that the following conditions   |
+// | are met:                                                             |
+// |                                                                      |
+// | Redistributions of source code must retain the above copyright       |
+// | notice, this list of conditions and the following disclaimer.        |
+// |                                                                      |
+// | Redistributions in binary form must reproduce the above copyright    |
+// | notice, this list of conditions and the following disclaimer in the  |
+// | documentation and/or other materials provided with the distribution. |
+// |                                                                      |
+// | Neither the name of Manuel Lemos, Tomas V.V.Cox, Stig. S. Bakken,    |
+// | Lukas Smith nor the names of his contributors may be used to endorse |
+// | or promote products derived from this software without specific prior|
+// | written permission.                                                  |
+// |                                                                      |
+// | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS  |
+// | "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT    |
+// | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS    |
+// | FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE      |
+// | REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,          |
+// | INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
+// | BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS|
+// |  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED  |
+// | AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT          |
+// | LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY|
+// | WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE          |
+// | POSSIBILITY OF SUCH DAMAGE.                                          |
+// +----------------------------------------------------------------------+
+// | Author: Lukas Smith <smith@pooteeweet.org>                           |
+// +----------------------------------------------------------------------+
+//
+// $Id: Common.php,v 1.21 2008/02/17 18:51:39 quipo Exp $
+//
+
+/**
+ * @package  MDB2
+ * @category Database
+ * @author   Lukas Smith <smith@pooteeweet.org>
+ */
+
+/**
+ * Base class for the function modules that is extended by each MDB2 driver
+ *
+ * To load this module in the MDB2 object:
+ * $mdb->loadModule('Function');
+ *
+ * @package  MDB2
+ * @category Database
+ * @author   Lukas Smith <smith@pooteeweet.org>
+ */
+class MDB2_Driver_Function_Common extends MDB2_Module_Common
+{
+    // {{{ executeStoredProc()
+
+    /**
+     * Execute a stored procedure and return any results
+     *
+     * @param string $name string that identifies the function to execute
+     * @param mixed  $params  array that contains the paramaters to pass the stored proc
+     * @param mixed   $types  array that contains the types of the columns in
+     *                        the result set
+     * @param mixed $result_class string which specifies which result class to use
+     * @param mixed $result_wrap_class string which specifies which class to wrap results in
+     *
+     * @return mixed a result handle or MDB2_OK on success, a MDB2 error on failure
+     * @access public
+     */
+    function &executeStoredProc($name, $params = null, $types = null, $result_class = true, $result_wrap_class = false)
+    {
+        $db =& $this->getDBInstance();
+        if (PEAR::isError($db)) {
+            return $db;
+        }
+
+        $error =& $db->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
+            'method not implemented', __FUNCTION__);
+        return $error;
+    }
+
+    // }}}
+    // {{{ functionTable()
+
+    /**
+     * return string for internal table used when calling only a function
+     *
+     * @return string for internal table used when calling only a function
+     * @access public
+     */
+    function functionTable()
+    {
+        return '';
+    }
+
+    // }}}
+    // {{{ now()
+
+    /**
+     * Return string to call a variable with the current timestamp inside an SQL statement
+     * There are three special variables for current date and time:
+     * - CURRENT_TIMESTAMP (date and time, TIMESTAMP type)
+     * - CURRENT_DATE (date, DATE type)
+     * - CURRENT_TIME (time, TIME type)
+     *
+     * @param string $type 'timestamp' | 'time' | 'date'
+     *
+     * @return string to call a variable with the current timestamp
+     * @access public
+     */
+    function now($type = 'timestamp')
+    {
+        switch ($type) {
+        case 'time':
+            return 'CURRENT_TIME';
+        case 'date':
+            return 'CURRENT_DATE';
+        case 'timestamp':
+        default:
+            return 'CURRENT_TIMESTAMP';
+        }
+    }
+
+    // }}}
+    // {{{ unixtimestamp()
+
+    /**
+     * return string to call a function to get the unix timestamp from a iso timestamp
+     *
+     * @param string $expression
+     *
+     * @return string to call a variable with the timestamp
+     * @access public
+     */
+    function unixtimestamp($expression)
+    {
+        $db =& $this->getDBInstance();
+        if (PEAR::isError($db)) {
+            return $db;
+        }
+
+        $error =& $db->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
+            'method not implemented', __FUNCTION__);
+        return $error;
+    }
+
+    // }}}
+    // {{{ substring()
+
+    /**
+     * return string to call a function to get a substring inside an SQL statement
+     *
+     * @return string to call a function to get a substring
+     * @access public
+     */
+    function substring($value, $position = 1, $length = null)
+    {
+        if (!is_null($length)) {
+            return "SUBSTRING($value FROM $position FOR $length)";
+        }
+        return "SUBSTRING($value FROM $position)";
+    }
+
+    // }}}
+    // {{{ replace()
+
+    /**
+     * return string to call a function to get replace inside an SQL statement.
+     *
+     * @return string to call a function to get a replace
+     * @access public
+     */
+    function replace($str, $from_str, $to_str)
+    {
+        return "REPLACE($str, $from_str , $to_str)";
+    }
+
+    // }}}
+    // {{{ concat()
+
+    /**
+     * Returns string to concatenate two or more string parameters
+     *
+     * @param string $value1
+     * @param string $value2
+     * @param string $values...
+     *
+     * @return string to concatenate two strings
+     * @access public
+     */
+    function concat($value1, $value2)
+    {
+        $args = func_get_args();
+        return "(".implode(' || ', $args).")";
+    }
+
+    // }}}
+    // {{{ random()
+
+    /**
+     * return string to call a function to get random value inside an SQL statement
+     *
+     * @return return string to generate float between 0 and 1
+     * @access public
+     */
+    function random()
+    {
+        return 'RAND()';
+    }
+
+    // }}}
+    // {{{ lower()
+
+    /**
+     * return string to call a function to lower the case of an expression
+     *
+     * @param string $expression
+     *
+     * @return return string to lower case of an expression
+     * @access public
+     */
+    function lower($expression)
+    {
+        return "LOWER($expression)";
+    }
+
+    // }}}
+    // {{{ upper()
+
+    /**
+     * return string to call a function to upper the case of an expression
+     *
+     * @param string $expression
+     *
+     * @return return string to upper case of an expression
+     * @access public
+     */
+    function upper($expression)
+    {
+        return "UPPER($expression)";
+    }
+
+    // }}}
+    // {{{ length()
+
+    /**
+     * return string to call a function to get the length of a string expression
+     *
+     * @param string $expression
+     *
+     * @return return string to get the string expression length
+     * @access public
+     */
+    function length($expression)
+    {
+        return "LENGTH($expression)";
+    }
+
+    // }}}
+    // {{{ guid()
+
+    /**
+     * Returns global unique identifier
+     *
+     * @return string to get global unique identifier
+     * @access public
+     */
+    function guid()
+    {
+        $db =& $this->getDBInstance();
+        if (PEAR::isError($db)) {
+            return $db;
+        }
+
+        $error =& $db->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
+            'method not implemented', __FUNCTION__);
+        return $error;
+    }
+
+    // }}}
+}
+?>
\ No newline at end of file
diff --git a/3dparty/MDB2/Driver/Function/mysql.php b/3dparty/MDB2/Driver/Function/mysql.php
new file mode 100644
index 00000000000..aff531c9f3a
--- /dev/null
+++ b/3dparty/MDB2/Driver/Function/mysql.php
@@ -0,0 +1,136 @@
+<?php
+// +----------------------------------------------------------------------+
+// | PHP versions 4 and 5                                                 |
+// +----------------------------------------------------------------------+
+// | Copyright (c) 1998-2008 Manuel Lemos, Tomas V.V.Cox,                 |
+// | Stig. S. Bakken, Lukas Smith                                         |
+// | All rights reserved.                                                 |
+// +----------------------------------------------------------------------+
+// | MDB2 is a merge of PEAR DB and Metabases that provides a unified DB  |
+// | API as well as database abstraction for PHP applications.            |
+// | This LICENSE is in the BSD license style.                            |
+// |                                                                      |
+// | Redistribution and use in source and binary forms, with or without   |
+// | modification, are permitted provided that the following conditions   |
+// | are met:                                                             |
+// |                                                                      |
+// | Redistributions of source code must retain the above copyright       |
+// | notice, this list of conditions and the following disclaimer.        |
+// |                                                                      |
+// | Redistributions in binary form must reproduce the above copyright    |
+// | notice, this list of conditions and the following disclaimer in the  |
+// | documentation and/or other materials provided with the distribution. |
+// |                                                                      |
+// | Neither the name of Manuel Lemos, Tomas V.V.Cox, Stig. S. Bakken,    |
+// | Lukas Smith nor the names of his contributors may be used to endorse |
+// | or promote products derived from this software without specific prior|
+// | written permission.                                                  |
+// |                                                                      |
+// | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS  |
+// | "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT    |
+// | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS    |
+// | FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE      |
+// | REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,          |
+// | INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
+// | BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS|
+// |  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED  |
+// | AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT          |
+// | LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY|
+// | WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE          |
+// | POSSIBILITY OF SUCH DAMAGE.                                          |
+// +----------------------------------------------------------------------+
+// | Author: Lukas Smith <smith@pooteeweet.org>                           |
+// +----------------------------------------------------------------------+
+//
+// $Id: mysql.php,v 1.12 2008/02/17 18:54:08 quipo Exp $
+//
+
+oc_require_once('MDB2/Driver/Function/Common.php');
+
+/**
+ * MDB2 MySQL driver for the function modules
+ *
+ * @package MDB2
+ * @category Database
+ * @author  Lukas Smith <smith@pooteeweet.org>
+ */
+class MDB2_Driver_Function_mysql extends MDB2_Driver_Function_Common
+{
+     // }}}
+    // {{{ executeStoredProc()
+
+    /**
+     * Execute a stored procedure and return any results
+     *
+     * @param string $name string that identifies the function to execute
+     * @param mixed  $params  array that contains the paramaters to pass the stored proc
+     * @param mixed   $types  array that contains the types of the columns in
+     *                        the result set
+     * @param mixed $result_class string which specifies which result class to use
+     * @param mixed $result_wrap_class string which specifies which class to wrap results in
+     * @return mixed a result handle or MDB2_OK on success, a MDB2 error on failure
+     * @access public
+     */
+    function &executeStoredProc($name, $params = null, $types = null, $result_class = true, $result_wrap_class = false)
+    {
+        $db =& $this->getDBInstance();
+        if (PEAR::isError($db)) {
+            return $db;
+        }
+
+        $query = 'CALL '.$name;
+        $query .= $params ? '('.implode(', ', $params).')' : '()';
+        return $db->query($query, $types, $result_class, $result_wrap_class);
+    }
+
+    // }}}
+    // {{{ unixtimestamp()
+
+    /**
+     * return string to call a function to get the unix timestamp from a iso timestamp
+     *
+     * @param string $expression
+     *
+     * @return string to call a variable with the timestamp
+     * @access public
+     */
+    function unixtimestamp($expression)
+    {
+        return 'UNIX_TIMESTAMP('. $expression.')';
+    }
+
+    // }}}
+    // {{{ concat()
+
+    /**
+     * Returns string to concatenate two or more string parameters
+     *
+     * @param string $value1
+     * @param string $value2
+     * @param string $values...
+     * @return string to concatenate two strings
+     * @access public
+     **/
+    function concat($value1, $value2)
+    {
+        $args = func_get_args();
+        return "CONCAT(".implode(', ', $args).")";
+    }
+
+    // }}}
+    // {{{ guid()
+
+    /**
+     * Returns global unique identifier
+     *
+     * @return string to get global unique identifier
+     * @access public
+     */
+    function guid()
+    {
+        return 'UUID()';
+    }
+
+    // }}}
+}
+?>
\ No newline at end of file
diff --git a/3dparty/MDB2/Driver/Function/pgsql.php b/3dparty/MDB2/Driver/Function/pgsql.php
new file mode 100644
index 00000000000..cb47ea57d9f
--- /dev/null
+++ b/3dparty/MDB2/Driver/Function/pgsql.php
@@ -0,0 +1,115 @@
+<?php
+// +----------------------------------------------------------------------+
+// | PHP versions 4 and 5                                                 |
+// +----------------------------------------------------------------------+
+// | Copyright (c) 1998-2008 Manuel Lemos, Tomas V.V.Cox,                 |
+// | Stig. S. Bakken, Lukas Smith                                         |
+// | All rights reserved.                                                 |
+// +----------------------------------------------------------------------+
+// | MDB2 is a merge of PEAR DB and Metabases that provides a unified DB  |
+// | API as well as database abstraction for PHP applications.            |
+// | This LICENSE is in the BSD license style.                            |
+// |                                                                      |
+// | Redistribution and use in source and binary forms, with or without   |
+// | modification, are permitted provided that the following conditions   |
+// | are met:                                                             |
+// |                                                                      |
+// | Redistributions of source code must retain the above copyright       |
+// | notice, this list of conditions and the following disclaimer.        |
+// |                                                                      |
+// | Redistributions in binary form must reproduce the above copyright    |
+// | notice, this list of conditions and the following disclaimer in the  |
+// | documentation and/or other materials provided with the distribution. |
+// |                                                                      |
+// | Neither the name of Manuel Lemos, Tomas V.V.Cox, Stig. S. Bakken,    |
+// | Lukas Smith nor the names of his contributors may be used to endorse |
+// | or promote products derived from this software without specific prior|
+// | written permission.                                                  |
+// |                                                                      |
+// | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS  |
+// | "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT    |
+// | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS    |
+// | FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE      |
+// | REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,          |
+// | INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
+// | BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS|
+// |  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED  |
+// | AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT          |
+// | LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY|
+// | WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE          |
+// | POSSIBILITY OF SUCH DAMAGE.                                          |
+// +----------------------------------------------------------------------+
+// | Author: Paul Cooper <pgc@ucecom.com>                                 |
+// +----------------------------------------------------------------------+
+//
+// $Id: pgsql.php,v 1.11 2008/11/09 19:46:50 quipo Exp $
+
+oc_require_once('MDB2/Driver/Function/Common.php');
+
+/**
+ * MDB2 MySQL driver for the function modules
+ *
+ * @package MDB2
+ * @category Database
+ * @author Lukas Smith <smith@pooteeweet.org>
+ */
+class MDB2_Driver_Function_pgsql extends MDB2_Driver_Function_Common
+{
+    // {{{ executeStoredProc()
+
+    /**
+     * Execute a stored procedure and return any results
+     *
+     * @param string $name string that identifies the function to execute
+     * @param mixed  $params  array that contains the paramaters to pass the stored proc
+     * @param mixed   $types  array that contains the types of the columns in
+     *                        the result set
+     * @param mixed $result_class string which specifies which result class to use
+     * @param mixed $result_wrap_class string which specifies which class to wrap results in
+     * @return mixed a result handle or MDB2_OK on success, a MDB2 error on failure
+     * @access public
+     */
+    function &executeStoredProc($name, $params = null, $types = null, $result_class = true, $result_wrap_class = false)
+    {
+        $db =& $this->getDBInstance();
+        if (PEAR::isError($db)) {
+            return $db;
+        }
+
+        $query = 'SELECT * FROM '.$name;
+        $query .= $params ? '('.implode(', ', $params).')' : '()';
+        return $db->query($query, $types, $result_class, $result_wrap_class);
+    }
+    // }}}
+    // {{{ unixtimestamp()
+
+    /**
+     * return string to call a function to get the unix timestamp from a iso timestamp
+     *
+     * @param string $expression
+     *
+     * @return string to call a variable with the timestamp
+     * @access public
+     */
+    function unixtimestamp($expression)
+    {
+        return 'EXTRACT(EPOCH FROM DATE_TRUNC(\'seconds\', CAST ((' . $expression . ') AS TIMESTAMP)))';
+    }
+
+    // }}}
+    // {{{ random()
+
+    /**
+     * return string to call a function to get random value inside an SQL statement
+     *
+     * @return return string to generate float between 0 and 1
+     * @access public
+     */
+    function random()
+    {
+        return 'RANDOM()';
+    }
+
+    // }}}
+}
+?>
\ No newline at end of file
diff --git a/3dparty/MDB2/Driver/Function/sqlite.php b/3dparty/MDB2/Driver/Function/sqlite.php
new file mode 100644
index 00000000000..f5499599dd5
--- /dev/null
+++ b/3dparty/MDB2/Driver/Function/sqlite.php
@@ -0,0 +1,162 @@
+<?php
+// +----------------------------------------------------------------------+
+// | PHP versions 4 and 5                                                 |
+// +----------------------------------------------------------------------+
+// | Copyright (c) 1998-2008 Manuel Lemos, Tomas V.V.Cox,                 |
+// | Stig. S. Bakken, Lukas Smith                                         |
+// | All rights reserved.                                                 |
+// +----------------------------------------------------------------------+
+// | MDB2 is a merge of PEAR DB and Metabases that provides a unified DB  |
+// | API as well as database abstraction for PHP applications.            |
+// | This LICENSE is in the BSD license style.                            |
+// |                                                                      |
+// | Redistribution and use in source and binary forms, with or without   |
+// | modification, are permitted provided that the following conditions   |
+// | are met:                                                             |
+// |                                                                      |
+// | Redistributions of source code must retain the above copyright       |
+// | notice, this list of conditions and the following disclaimer.        |
+// |                                                                      |
+// | Redistributions in binary form must reproduce the above copyright    |
+// | notice, this list of conditions and the following disclaimer in the  |
+// | documentation and/or other materials provided with the distribution. |
+// |                                                                      |
+// | Neither the name of Manuel Lemos, Tomas V.V.Cox, Stig. S. Bakken,    |
+// | Lukas Smith nor the names of his contributors may be used to endorse |
+// | or promote products derived from this software without specific prior|
+// | written permission.                                                  |
+// |                                                                      |
+// | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS  |
+// | "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT    |
+// | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS    |
+// | FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE      |
+// | REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,          |
+// | INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
+// | BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS|
+// |  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED  |
+// | AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT          |
+// | LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY|
+// | WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE          |
+// | POSSIBILITY OF SUCH DAMAGE.                                          |
+// +----------------------------------------------------------------------+
+// | Author: Lukas Smith <smith@pooteeweet.org>                           |
+// +----------------------------------------------------------------------+
+//
+// $Id: sqlite.php,v 1.10 2008/02/17 18:54:08 quipo Exp $
+//
+
+oc_require_once('MDB2/Driver/Function/Common.php');
+
+/**
+ * MDB2 SQLite driver for the function modules
+ *
+ * @package MDB2
+ * @category Database
+ * @author  Lukas Smith <smith@pooteeweet.org>
+ */
+class MDB2_Driver_Function_sqlite extends MDB2_Driver_Function_Common
+{
+    // {{{ constructor
+
+    /**
+     * Constructor
+     */
+    function __construct($db_index)
+    {
+        parent::__construct($db_index);
+        // create all sorts of UDFs
+    }
+
+    // {{{ now()
+
+    /**
+     * Return string to call a variable with the current timestamp inside an SQL statement
+     * There are three special variables for current date and time.
+     *
+     * @return string to call a variable with the current timestamp
+     * @access public
+     */
+    function now($type = 'timestamp')
+    {
+        switch ($type) {
+        case 'time':
+            return 'time(\'now\')';
+        case 'date':
+            return 'date(\'now\')';
+        case 'timestamp':
+        default:
+            return 'datetime(\'now\')';
+        }
+    }
+
+    // }}}
+    // {{{ unixtimestamp()
+
+    /**
+     * return string to call a function to get the unix timestamp from a iso timestamp
+     *
+     * @param string $expression
+     *
+     * @return string to call a variable with the timestamp
+     * @access public
+     */
+    function unixtimestamp($expression)
+    {
+        return 'strftime("%s",'. $expression.', "utc")';
+    }
+
+    // }}}
+    // {{{ substring()
+
+    /**
+     * return string to call a function to get a substring inside an SQL statement
+     *
+     * @return string to call a function to get a substring
+     * @access public
+     */
+    function substring($value, $position = 1, $length = null)
+    {
+        if (!is_null($length)) {
+            return "substr($value,$position,$length)";
+        }
+        return "substr($value,$position,length($value))";
+    }
+
+    // }}}
+    // {{{ random()
+
+    /**
+     * return string to call a function to get random value inside an SQL statement
+     *
+     * @return return string to generate float between 0 and 1
+     * @access public
+     */
+    function random()
+    {
+        return '((RANDOM()+2147483648)/4294967296)';
+    }
+
+    // }}}
+    // {{{ replace()
+
+    /**
+     * return string to call a function to get a replacement inside an SQL statement.
+     *
+     * @return string to call a function to get a replace
+     * @access public
+     */
+    function replace($str, $from_str, $to_str)
+    {
+        $db =& $this->getDBInstance();
+        if (PEAR::isError($db)) {
+            return $db;
+        }
+
+        $error =& $db->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
+            'method not implemented', __FUNCTION__);
+        return $error;
+    }
+
+    // }}}
+}
+?>