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<?php

/* vim: set expandtab tabstop=4 shiftwidth=4 foldmethod=marker: */

// +----------------------------------------------------------------------+

// | PHP Version 4                                                        |

// +----------------------------------------------------------------------+

// | Copyright (c) 1997-2004 The PHP Group                                |

// +----------------------------------------------------------------------+

// | This source file is subject to version 2.02 of the PHP license,      |

// | that is bundled with this package in the file LICENSE, and is        |

// | available at through the world-wide-web at                           |

// | http://www.php.net/license/2_02.txt.                                 |

// | If you did not receive a copy of the PHP license and are unable to   |

// | obtain it through the world-wide-web, please send a note to          |

// | license@php.net so we can mail you a copy immediately.               |

// +----------------------------------------------------------------------+

// | Author: Stig Bakken <ssb@php.net>                                    |

// |         Tomas V.V.Cox <cox@idecnet.com>                              |

// | Maintainer: Daniel Convissor <danielc@php.net>                       |

// +----------------------------------------------------------------------+

//

// $Id$

require_once 'PEAR.php';

/**

 * DB_common is a base class for DB implementations, and must be

 * inherited by all such

 *

 * @package  DB

 * @version  $Id$

 * @category Database

 * @author   Stig Bakken <ssb@php.net>

 * @author   Tomas V.V.Cox <cox@idecnet.com>

 */

class DB_common extends PEAR

{

    // {{{ properties

    /**

     * assoc of capabilities for this DB implementation

     * $features['limit'] =>  'emulate' => emulate with fetch row by number

     *                        'alter'   => alter the query

     *                        false     => skip rows

     * @var array

     */

    var $features = array();

    /**

     * assoc mapping native error codes to DB ones

     * @var array

     */

    var $errorcode_map = array();

    /**

     * DB type (mysql, oci8, odbc etc.)

     * @var string

     */

    var $phptype;

    /**

     * @var string

     */

    var $prepare_tokens;

    /**

     * @var string

     */

    var $prepare_types;

    /**

     * @var string

     */

    var $prepared_queries;

    /**

     * @var integer

     */

    var $prepare_maxstmt = 0;

    /**

     * @var string

     */

    var $last_query = '';

    /**

     * @var integer

     */

    var $fetchmode = DB_FETCHMODE_ORDERED;

    /**

     * @var string

     */

    var $fetchmode_object_class = 'stdClass';

    /**

     * Run-time configuration options.

     *

     * The 'optimize' option has been deprecated.  Use the 'portability'

     * option instead.

     *

     * @see DB_common::setOption()

     * @var array

     */

    var $options = array(

        'persistent' => false,

        'ssl' => false,

        'debug' => 0,

        'seqname_format' => '%s_seq',

        'autofree' => false,

        'portability' => DB_PORTABILITY_NONE,

        'optimize' => 'performance',  // Deprecated.  Use 'portability'.

    );

    /**

     * DB handle

     * @var resource

     */

    var $dbh;

    // }}}

    // {{{ toString()

    /**

     * String conversation

     *

     * @return string

     * @access private

     */

    function toString()

    {

        $info = strtolower(get_class($this));

        $info .=  ': (phptype=' . $this->phptype .

                  ', dbsyntax=' . $this->dbsyntax .

                  ')';

        if ($this->connection) {

            $info .= ' [connected]';

        }

        return $info;

    }

    // }}}

    // {{{ constructor

    /**

     * Constructor

     */

    function DB_common()

    {

        $this->PEAR('DB_Error');

    }

    // }}}

    // {{{ quoteString()

    /**

     * DEPRECATED: Quotes a string so it can be safely used within string

     * delimiters in a query

     *

     * @return string quoted string

     *

     * @see DB_common::quoteSmart(), DB_common::escapeSimple()

     * @deprecated  Deprecated in release 1.2 or lower

     * @internal

     */

    function quoteString($string)

    {

        $string = $this->quote($string);

        if ($string{0} == "'") {

            return substr($string, 1, -1);

        }

        return $string;

    }

    // }}}

    // {{{ quote()

    /**

     * DEPRECATED: Quotes a string so it can be safely used in a query

     *

     * @param string $string the input string to quote

     *

     * @return string The NULL string or the string quotes

     *                in magic_quote_sybase style

     *

     * @see DB_common::quoteSmart(), DB_common::escapeSimple()

     * @deprecated  Deprecated in release 1.6.0

     * @internal

     */

    function quote($string = null)

    {

        return ($string === null) ? 'NULL' : "'".str_replace("'", "''", $string)."'";

    }

    // }}}

    // {{{ quoteIdentifier()

    /**

     * Quote a string so it can be safely used as a table or column name

     *

     * Delimiting style depends on which database driver is being used.

     *

     * NOTE: just because you CAN use delimited identifiers doesn't mean

     * you SHOULD use them.  In general, they end up causing way more

     * problems than they solve.

     *

     * Portability is broken by using the following characters inside

     * delimited identifiers:

     *   + backtick (<kbd>`</kbd>) -- due to MySQL

     *   + double quote (<kbd>"</kbd>) -- due to Oracle

     *   + brackets (<kbd>[</kbd> or <kbd>]</kbd>) -- due to Access

     *

     * Delimited identifiers are known to generally work correctly under

     * the following drivers:

     *   + mssql

     *   + mysql

     *   + mysqli

     *   + oci8

     *   + odbc(access)

     *   + odbc(db2)

     *   + pgsql

     *   + sqlite

     *   + sybase

     *

     * InterBase doesn't seem to be able to use delimited identifiers

     * via PHP 4.  They work fine under PHP 5.

     *

     * @param string $str  identifier name to be quoted

     *

     * @return string  quoted identifier string

     *

     * @since 1.6.0

     * @access public

     */

    function quoteIdentifier($str)

    {

        return '"' . str_replace('"', '""', $str) . '"';

    }

    // }}}

    // {{{ quoteSmart()

    /**

     * Format input so it can be safely used in a query

     *

     * The output depends on the PHP data type of input and the database

     * type being used.

     *

     * @param mixed $in  data to be quoted

     *

     * @return mixed  the format of the results depends on the input's

     *                PHP type:

     *

     * <ul>

     *  <li>

     *    <kbd>input</kbd> -> <samp>returns</samp>

     *  </li>

     *  <li>

     *    <kbd>null</kbd> -> the string <samp>NULL</samp>

     *  </li>

     *  <li>

     *    <kbd>integer</kbd> or <kbd>double</kbd> -> the unquoted number

     *  </li>

     *  <li>

     *    &type.bool; -> output depends on the driver in use

     *    Most drivers return integers: <samp>1</samp> if

     *    <kbd>true</kbd> or <samp>0</samp> if

     *    <kbd>false</kbd>.

     *    Some return strings: <samp>TRUE</samp> if

     *    <kbd>true</kbd> or <samp>FALSE</samp> if

     *    <kbd>false</kbd>.

     *    Finally one returns strings: <samp>T</samp> if

     *    <kbd>true</kbd> or <samp>F</samp> if

     *    <kbd>false</kbd>. Here is a list of each DBMS,

     *    the values returned and the suggested column type:

     *    <ul>

     *      <li>

     *        <kbd>dbase</kbd> -> <samp>T/F</samp>

     *        (<kbd>Logical</kbd>)

     *      </li>

     *      <li>

     *        <kbd>fbase</kbd> -> <samp>TRUE/FALSE</samp>

     *        (<kbd>BOOLEAN</kbd>)

     *      </li>

     *      <li>

     *        <kbd>ibase</kbd> -> <samp>1/0</samp>

     *        (<kbd>SMALLINT</kbd>) [1]

     *      </li>

     *      <li>

     *        <kbd>ifx</kbd> -> <samp>1/0</samp>

     *        (<kbd>SMALLINT</kbd>) [1]

     *      </li>

     *      <li>

     *        <kbd>msql</kbd> -> <samp>1/0</samp>

     *        (<kbd>INTEGER</kbd>)

     *      </li>

     *      <li>

     *        <kbd>mssql</kbd> -> <samp>1/0</samp>

     *        (<kbd>BIT</kbd>)

     *      </li>

     *      <li>

     *        <kbd>mysql</kbd> -> <samp>1/0</samp>

     *        (<kbd>TINYINT(1)</kbd>)

     *      </li>

     *      <li>

     *        <kbd>mysqli</kbd> -> <samp>1/0</samp>

     *        (<kbd>TINYINT(1)</kbd>)

     *      </li>

     *      <li>

     *        <kbd>oci8</kbd> -> <samp>1/0</samp>

     *        (<kbd>NUMBER(1)</kbd>)

     *      </li>

     *      <li>

     *        <kbd>odbc</kbd> -> <samp>1/0</samp>

     *        (<kbd>SMALLINT</kbd>) [1]

     *      </li>

     *      <li>

     *        <kbd>pgsql</kbd> -> <samp>TRUE/FALSE</samp>

     *        (<kbd>BOOLEAN</kbd>)

     *      </li>

     *      <li>

     *        <kbd>sqlite</kbd> -> <samp>1/0</samp>

     *        (<kbd>INTEGER</kbd>)

     *      </li>

     *      <li>

     *        <kbd>sybase</kbd> -> <samp>1/0</samp>

     *        (<kbd>TINYINT(1)</kbd>)

     *      </li>

     *    </ul>

     *    [1] Accommodate the lowest common denominator because not all

     *    versions of have <kbd>BOOLEAN</kbd>.

     *  </li>

     *  <li>

     *    other (including strings and numeric strings) ->

     *    the data with single quotes escaped by preceeding

     *    single quotes, backslashes are escaped by preceeding

     *    backslashes, then the whole string is encapsulated

     *    between single quotes

     *  </li>

     * </ul>

     *

     * @since 1.6.0

     * @see DB_common::escapeSimple()

     * @access public

     */

    function quoteSmart($in)

    {

        if (is_int($in) || is_double($in)) {

            return $in;

        } elseif (is_bool($in)) {

            return $in ? 1 : 0;

        } elseif (is_null($in)) {

            return 'NULL';

        } else {

            return "'" . $this->escapeSimple($in) . "'";

        }

    }

    // }}}

    // {{{ escapeSimple()

    /**

     * Escape a string according to the current DBMS's standards

     *

     * In SQLite, this makes things safe for inserts/updates, but may

     * cause problems when performing text comparisons against columns

     * containing binary data. See the

     * {@link http://php.net/sqlite_escape_string PHP manual} for more info.

     *

     * @param string $str  the string to be escaped

     *

     * @return string  the escaped string

     *

     * @since 1.6.0

     * @see DB_common::quoteSmart()

     * @access public

     */

    function escapeSimple($str) {

        return str_replace("'", "''", $str);

    }

    // }}}

    // {{{ provides()

    /**

     * Tell whether a DB implementation or its backend extension

     * supports a given feature

     *

     * @param array $feature name of the feature (see the DB class doc)

     * @return bool whether this DB implementation supports $feature

     * @access public

     */

    function provides($feature)

    {

        return $this->features[$feature];

    }

    // }}}

    // {{{ errorCode()

    /**

     * Map native error codes to DB's portable ones

     *

     * Requires that the DB implementation's constructor fills

     * in the <var>$errorcode_map</var> property.

     *

     * @param mixed  $nativecode  the native error code, as returned by the

     * backend database extension (string or integer)

     *

     * @return int a portable DB error code, or DB_ERROR if this DB

     * implementation has no mapping for the given error code.

     *

     * @access public

     */

    function errorCode($nativecode)

    {

        if (isset($this->errorcode_map[$nativecode])) {

            return $this->errorcode_map[$nativecode];

        }

        // Fall back to DB_ERROR if there was no mapping.

        return DB_ERROR;

    }

    // }}}

    // {{{ errorMessage()

    /**

     * Map a DB error code to a textual message.  This is actually

     * just a wrapper for DB::errorMessage()

     *

     * @param integer $dbcode the DB error code

     *

     * @return string the corresponding error message, of false

     * if the error code was unknown

     *

     * @access public

     */

    function errorMessage($dbcode)

    {

        return DB::errorMessage($this->errorcode_map[$dbcode]);

    }

    // }}}

    // {{{ raiseError()

    /**

     * Communicate an error and invoke error callbacks, etc

     *

     * Basically a wrapper for PEAR::raiseError without the message string.

     *

     * @param mixed    integer error code, or a PEAR error object (all

     *                 other parameters are ignored if this parameter is

     *                 an object

     *

     * @param int      error mode, see PEAR_Error docs

     *

     * @param mixed    If error mode is PEAR_ERROR_TRIGGER, this is the

     *                 error level (E_USER_NOTICE etc).  If error mode is

     *                 PEAR_ERROR_CALLBACK, this is the callback function,

     *                 either as a function name, or as an array of an

     *                 object and method name.  For other error modes this

     *                 parameter is ignored.

     *

     * @param string   Extra debug information.  Defaults to the last

     *                 query and native error code.

     *

     * @param mixed    Native error code, integer or string depending the

     *                 backend.

     *

     * @return object  a PEAR error object

     *

     * @access public

     * @see PEAR_Error

     */

    function &raiseError($code = DB_ERROR, $mode = null, $options = null,

                         $userinfo = null, $nativecode = null)

    {

        // The error is yet a DB error object

        if (is_object($code)) {

            // because we the static PEAR::raiseError, our global

            // handler should be used if it is set

            if ($mode === null && !empty($this->_default_error_mode)) {

                $mode    = $this->_default_error_mode;

                $options = $this->_default_error_options;

            }

            $tmp = PEAR::raiseError($code, null, $mode, $options, null, null, true);

            return $tmp;

        }

        if ($userinfo === null) {

            $userinfo = $this->last_query;

        }

        if ($nativecode) {

            $userinfo .= ' [nativecode=' . trim($nativecode) . ']';

        }

        $tmp = PEAR::raiseError(null, $code, $mode, $options, $userinfo,

                                'DB_Error', true);

        return $tmp;

    }

    // }}}

    // {{{ setFetchMode()

    /**

     * Sets which fetch mode should be used by default on queries

     * on this connection

     *

     * @param integer $fetchmode DB_FETCHMODE_ORDERED or

     *        DB_FETCHMODE_ASSOC, possibly bit-wise OR'ed with

     *        DB_FETCHMODE_FLIPPED.

     *

     * @param string $object_class The class of the object

     *                      to be returned by the fetch methods when

     *                      the DB_FETCHMODE_OBJECT mode is selected.

     *                      If no class is specified by default a cast

     *                      to object from the assoc array row will be done.

     *                      There is also the posibility to use and extend the

     *                      'DB_row' class.

     *

     * @see DB_FETCHMODE_ORDERED

     * @see DB_FETCHMODE_ASSOC

     * @see DB_FETCHMODE_FLIPPED

     * @see DB_FETCHMODE_OBJECT

     * @see DB_row::DB_row()

     * @access public

     */

    function setFetchMode($fetchmode, $object_class = 'stdClass')

    {

        switch ($fetchmode) {

            case DB_FETCHMODE_OBJECT:

                $this->fetchmode_object_class = $object_class;

            case DB_FETCHMODE_ORDERED:

            case DB_FETCHMODE_ASSOC:

                $this->fetchmode = $fetchmode;

                break;

            default:

                return $this->raiseError('invalid fetchmode mode');

        }

    }

    // }}}

    // {{{ setOption()

    /**

     * Set run-time configuration options for PEAR DB

     *

     * Options, their data types, default values and description:

     * <ul>

     * <li>

     * <var>autofree</var> <kbd>boolean</kbd> = <samp>false</samp>

     *      <br />should results be freed automatically when there are no

     *            more rows?

     * </li><li>

     * <var>debug</var> <kbd>integer</kbd> = <samp>0</samp>

     *      <br />debug level

     * </li><li>

     * <var>persistent</var> <kbd>boolean</kbd> = <samp>false</samp>

     *      <br />should the connection be persistent?

     * </li><li>

     * <var>portability</var> <kbd>integer</kbd> = <samp>DB_PORTABILITY_NONE</samp>

     *      <br />portability mode constant (see below)

     * </li><li>

     * <var>seqname_format</var> <kbd>string</kbd> = <samp>%s_seq</samp>

     *      <br />the sprintf() format string used on sequence names.  This

     *            format is applied to sequence names passed to

     *            createSequence(), nextID() and dropSequence().

     * </li><li>

     * <var>ssl</var> <kbd>boolean</kbd> = <samp>false</samp>

     *      <br />use ssl to connect?

     * </li>

     * </ul>

     *

     * -----------------------------------------

     *

     * PORTABILITY MODES

     *

     * These modes are bitwised, so they can be combined using <kbd>|</kbd>

     * and removed using <kbd>^</kbd>.  See the examples section below on how

     * to do this.

     *

     * <samp>DB_PORTABILITY_NONE</samp>

     * turn off all portability features

     *

     * This mode gets automatically turned on if the deprecated

     * <var>optimize</var> option gets set to <samp>performance</samp>.

     *

     *

     * <samp>DB_PORTABILITY_LOWERCASE</samp>

     * convert names of tables and fields to lower case when using

     * <kbd>get*()</kbd>, <kbd>fetch*()</kbd> and <kbd>tableInfo()</kbd>

     *

     * This mode gets automatically turned on in the following databases

     * if the deprecated option <var>optimize</var> gets set to

     * <samp>portability</samp>:

     * + oci8

     *

     *

     * <samp>DB_PORTABILITY_RTRIM</samp>

     * right trim the data output by <kbd>get*()</kbd> <kbd>fetch*()</kbd>

     *

     *

     * <samp>DB_PORTABILITY_DELETE_COUNT</samp>

     * force reporting the number of rows deleted

     *

     * Some DBMS's don't count the number of rows deleted when performing

     * simple <kbd>DELETE FROM tablename</kbd> queries.  This portability

     * mode tricks such DBMS's into telling the count by adding

     * <samp>WHERE 1=1</samp> to the end of <kbd>DELETE</kbd> queries.

     *

     * This mode gets automatically turned on in the following databases

     * if the deprecated option <var>optimize</var> gets set to

     * <samp>portability</samp>:

     * + fbsql

     * + mysql

     * + mysqli

     * + sqlite

     *

     *

     * <samp>DB_PORTABILITY_NUMROWS</samp>

     * enable hack that makes <kbd>numRows()</kbd> work in Oracle

     *

     * This mode gets automatically turned on in the following databases

     * if the deprecated option <var>optimize</var> gets set to

     * <samp>portability</samp>:

     * + oci8

     *

     *

     * <samp>DB_PORTABILITY_ERRORS</samp>

     * makes certain error messages in certain drivers compatible

     * with those from other DBMS's

     *

     * + mysql, mysqli:  change unique/primary key constraints

     *   DB_ERROR_ALREADY_EXISTS -> DB_ERROR_CONSTRAINT

     *

     * + odbc(access):  MS's ODBC driver reports 'no such field' as code

     *   07001, which means 'too few parameters.'  When this option is on

     *   that code gets mapped to DB_ERROR_NOSUCHFIELD.

     *   DB_ERROR_MISMATCH -> DB_ERROR_NOSUCHFIELD

     *

     *

     * <samp>DB_PORTABILITY_NULL_TO_EMPTY</samp>

     * convert null values to empty strings in data output by get*() and

     * fetch*().  Needed because Oracle considers empty strings to be null,

     * while most other DBMS's know the difference between empty and null.

     *

     *

     * <samp>DB_PORTABILITY_ALL</samp>

     * turn on all portability features

     *

     * -----------------------------------------

     *

     * Example 1. Simple setOption() example

     * <code> <?php

     * $dbh->setOption('autofree', true);

     * ?></code>

     *

     * Example 2. Portability for lowercasing and trimming

     * <code> <?php

     * $dbh->setOption('portability',

     *                  DB_PORTABILITY_LOWERCASE | DB_PORTABILITY_RTRIM);

     * ?></code>

     *

     * Example 3. All portability options except trimming

     * <code> <?php

     * $dbh->setOption('portability',

     *                  DB_PORTABILITY_ALL ^ DB_PORTABILITY_RTRIM);

     * ?></code>

     *

     * @param string $option option name

     * @param mixed  $value value for the option

     *

     * @return int  DB_OK on success.  DB_Error object on failure.

     *

     * @see DB_common::$options

     */

    function setOption($option, $value)

    {

        if (isset($this->options[$option])) {

            $this->options[$option] = $value;

            /*

             * Backwards compatibility check for the deprecated 'optimize'

             * option.  Done here in case settings change after connecting.

             */

            if ($option == 'optimize') {

                if ($value == 'portability') {

                    switch ($this->phptype) {

                        case 'oci8':

                            $this->options['portability'] =

                                    DB_PORTABILITY_LOWERCASE |

                                    DB_PORTABILITY_NUMROWS;

                            break;

                        case 'fbsql':

                        case 'mysql':

                        case 'mysqli':

                        case 'sqlite':

                            $this->options['portability'] =

                                    DB_PORTABILITY_DELETE_COUNT;

                            break;

                    }

                } else {

                    $this->options['portability'] = DB_PORTABILITY_NONE;

                }

            }

            return DB_OK;

        }

        return $this->raiseError("unknown option $option");

    }

    // }}}

    // {{{ getOption()

    /**

     * Returns the value of an option

     *

     * @param string $option option name

     *

     * @return mixed the option value

     */

    function getOption($option)

    {

        if (isset($this->options[$option])) {

            return $this->options[$option];

        }

        return $this->raiseError("unknown option $option");

    }

    // }}}

    // {{{ prepare()

    /**

     * Prepares a query for multiple execution with execute()

     *

     * Creates a query that can be run multiple times.  Each time it is run,

     * the placeholders, if any, will be replaced by the contents of

     * execute()'s $data argument.

     *

     * Three types of placeholders can be used:

     *   + <kbd>?</kbd>  scalar value (i.e. strings, integers).  The system

     *                   will automatically quote and escape the data.

     *   + <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)

     *

     * Example 1.

     * <code> <?php

     * $sth = $dbh->prepare('INSERT INTO tbl (a, b, c) VALUES (?, !, &)');

     * $data = array(

     *     "John's text",

     *     "'it''s good'",

     *     'filename.txt'

     * );

     * $res = $dbh->execute($sth, $data);

     * ?></code>

     *

     * Use backslashes to escape placeholder characters if you don't want

     * them to be interpreted as placeholders:

     * <pre>

     *    "UPDATE foo SET col=? WHERE col='over \& under'"

     * </pre>

     *

     * With some database backends, this is emulated.

     *

     * {@internal ibase and oci8 have their own prepare() methods.}}

     *

     * @param string $query query to be prepared

     *

     * @return mixed DB statement resource on success. DB_Error on failure.

     *

     * @see DB_common::execute()

     * @access public

     */

    function prepare($query)

    {

        $tokens   = preg_split('/((?<!\\\)[&?!])/', $query, -1,

                               PREG_SPLIT_DELIM_CAPTURE);

        $token     = 0;

        $types     = array();

        $newtokens = array();

        foreach ($tokens as $val) {

            switch ($val) {

                case '?':

                    $types[$token++] = DB_PARAM_SCALAR;

                    break;

                case '&':

                    $types[$token++] = DB_PARAM_OPAQUE;

                    break;

                case '!':

                    $types[$token++] = DB_PARAM_MISC;

                    break;

                default:

                    $newtokens[] = preg_replace('/\\\([&?!])/', "\\1", $val);

            }

        }

        $this->prepare_tokens[] = &$newtokens;

        end($this->prepare_tokens);

        $k = key($this->prepare_tokens);

        $this->prepare_types[$k] = $types;

        $this->prepared_queries[$k] = implode(' ', $newtokens);

        return $k;

    }

    // }}}

    // {{{ autoPrepare()

    /**

     * Automaticaly generate an insert or update query and pass it to prepare()

     *

     * @param string $table name of the table

     * @param array $table_fields ordered array containing the fields names

     * @param int $mode type of query to make (DB_AUTOQUERY_INSERT or DB_AUTOQUERY_UPDATE)

     * @param string $where in case of update queries, this string will be put after the sql WHERE statement

     * @return resource handle for the query

     * @see DB_common::prepare(), DB_common::buildManipSQL()

     * @access public

     */

    function autoPrepare($table, $table_fields, $mode = DB_AUTOQUERY_INSERT, $where = false)

    {

        $query = $this->buildManipSQL($table, $table_fields, $mode, $where);

        return $this->prepare($query);

    }

    // }}}

    // {{{ autoExecute()

    /**

     * Automaticaly generate an insert or update query and call prepare()

     * and execute() with it

     *

     * @param string $table name of the table

     * @param array $fields_values assoc ($key=>$value) where $key is a field name and $value its value

     * @param int $mode type of query to make (DB_AUTOQUERY_INSERT or DB_AUTOQUERY_UPDATE)

     * @param string $where in case of update queries, this string will be put after the sql WHERE statement

     * @return mixed  a new DB_Result or a DB_Error when fail

     * @see DB_common::autoPrepare(), DB_common::buildManipSQL()

     * @access public

     */

    function autoExecute($table, $fields_values, $mode = DB_AUTOQUERY_INSERT, $where = false)

    {

        $sth = $this->autoPrepare($table, array_keys($fields_values), $mode, $where);

        $ret =& $this->execute($sth, array_values($fields_values));

        $this->freePrepared($sth);

        return $ret;

    }

    // }}}

    // {{{ buildManipSQL()

    /**

     * Make automaticaly an sql query for prepare()

     *

     * Example : buildManipSQL('table_sql', array('field1', 'field2', 'field3'), DB_AUTOQUERY_INSERT)

     *           will return the string : INSERT INTO table_sql (field1,field2,field3) VALUES (?,?,?)

     * NB : - This belongs more to a SQL Builder class, but this is a simple facility

     *      - Be carefull ! If you don't give a $where param with an UPDATE query, all

     *        the records of the table will be updated !

     *

     * @param string $table name of the table

     * @param array $table_fields ordered array containing the fields names

     * @param int $mode type of query to make (DB_AUTOQUERY_INSERT or DB_AUTOQUERY_UPDATE)

     * @param string $where in case of update queries, this string will be put after the sql WHERE statement

     * @return string sql query for prepare()

     * @access public

     */

    function buildManipSQL($table, $table_fields, $mode, $where = false)

    {

        if (count($table_fields) == 0) {

            $this->raiseError(DB_ERROR_NEED_MORE_DATA);

        }

        $first = true;

        switch ($mode) {

            case DB_AUTOQUERY_INSERT:

                $values = '';

                $names = '';

                foreach ($table_fields as $value) {

                    if ($first) {

                        $first = false;

                    } else {

                        $names .= ',';

                        $values .= ',';

                    }

                    $names .= $value;

                    $values .= '?';

                }

                return "INSERT INTO $table ($names) VALUES ($values)";

            case DB_AUTOQUERY_UPDATE:

                $set = '';

                foreach ($table_fields as $value) {

                    if ($first) {

                        $first = false;

                    } else {

                        $set .= ',';

                    }

                    $set .= "$value = ?";

                }

                $sql = "UPDATE $table SET $set";

                if ($where) {

                    $sql .= " WHERE $where";

                }

                return $sql;

            default:

                $this->raiseError(DB_ERROR_SYNTAX);

        }

    }

    // }}}

    // {{{ execute()

    /**

     * Executes a DB statement prepared with prepare()

     *

     * Example 1.

     * <code> <?php

     * $sth = $dbh->prepare('INSERT INTO tbl (a, b, c) VALUES (?, !, &)');

     * $data = array(

     *     "John's text",

     *     "'it''s good'",

     *     'filename.txt'

     * );

     * $res =& $dbh->execute($sth, $data);

     * ?></code>

     *

     * @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 placeholder for non-array

     *                      parameters or 1 placeholder per array element.

     *

     * @return object  a new DB_Result or a DB_Error when fail

     *

     * {@internal ibase and oci8 have their own execute() methods.}}

     *

     * @see DB_common::prepare()

     * @access public

     */

    function &execute($stmt, $data = array())

    {

        $realquery = $this->executeEmulateQuery($stmt, $data);

        if (DB::isError($realquery)) {

            return $realquery;

        }

        $result = $this->simpleQuery($realquery);

        if (DB::isError($result) || $result === DB_OK) {

            return $result;

        } else {

            $tmp =& new DB_result($this, $result);

            return $tmp;

        }

    }

    // }}}

    // {{{ executeEmulateQuery()

    /**

     * Emulates the execute statement, when not supported

     *

     * @param resource  $stmt  a DB statement resource returned from execute()

     * @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 placeholder for non-array

     *                      parameters or 1 placeholder per array element.

     *

     * @return mixed a string containing the real query run when emulating

     *               prepare/execute.  A DB error code is returned on failure.

     *

     * @see DB_common::execute()

     * @access private

     */

    function executeEmulateQuery($stmt, $data = array())

    {

        if (!is_array($data)) {

            $data = array($data);

        }

        if (count($this->prepare_types[$stmt]) != count($data)) {

            $this->last_query = $this->prepared_queries[$stmt];

            return $this->raiseError(DB_ERROR_MISMATCH);

        }

        $realquery = $this->prepare_tokens[$stmt][0];