<?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: Tomas V.V.Cox <cox@idecnet.com>                              |
// | Maintainer: Daniel Convissor <danielc@php.net>                       |
// +----------------------------------------------------------------------+
//
// $Id: ifx.php,v 1.2 2005/07/22 05:10:13 max Exp $


// Legend:
// For more info on Informix errors see:
// http://www.informix.com/answers/english/ierrors.htm
//
// TODO:
//  - set needed env Informix vars on connect
//  - implement native prepare/execute


require_once PEAR_DIR . 'DB/common.php';

/**
 * Database independent query interface definition for PHP's Informix
 * extension.
 *
 * @package  DB
 * @version  $Id: ifx.php,v 1.2 2005/07/22 05:10:13 max Exp $
 * @category Database
 * @author   Tomas V.V.Cox <cox@idecnet.com>
 */
class DB_ifx extends DB_common
{
    // {{{ properties

    var $connection;
    var $affected = 0;
    var $dsn = array();
    var $transaction_opcount = 0;
    var $autocommit = true;
    var $fetchmode = DB_FETCHMODE_ORDERED; /* Default fetch mode */

    // }}}
    // {{{ constructor

    function DB_ifx()
    {
        $this->phptype = 'ifx';
        $this->dbsyntax = 'ifx';
        $this->features = array(
            'prepare' => false,
            'pconnect' => true,
            'transactions' => true,
            'limit' => 'emulate'
        );
        $this->errorcode_map = array(
            '-201'    => DB_ERROR_SYNTAX,
            '-206'    => DB_ERROR_NOSUCHTABLE,
            '-217'    => DB_ERROR_NOSUCHFIELD,
            '-239'    => DB_ERROR_CONSTRAINT,
            '-253'    => DB_ERROR_SYNTAX,
            '-292'    => DB_ERROR_CONSTRAINT_NOT_NULL,
            '-310'    => DB_ERROR_ALREADY_EXISTS,
            '-329'    => DB_ERROR_NODBSELECTED,
            '-346'    => DB_ERROR_CONSTRAINT,
            '-386'    => DB_ERROR_CONSTRAINT_NOT_NULL,
            '-391'    => DB_ERROR_CONSTRAINT_NOT_NULL,
            '-554'    => DB_ERROR_SYNTAX,
            '-691'    => DB_ERROR_CONSTRAINT,
            '-703'    => DB_ERROR_CONSTRAINT_NOT_NULL,
            '-1204'   => DB_ERROR_INVALID_DATE,
            '-1205'   => DB_ERROR_INVALID_DATE,
            '-1206'   => DB_ERROR_INVALID_DATE,
            '-1209'   => DB_ERROR_INVALID_DATE,
            '-1210'   => DB_ERROR_INVALID_DATE,
            '-1212'   => DB_ERROR_INVALID_DATE,
            '-1213'   => DB_ERROR_INVALID_NUMBER,
        );
    }

    // }}}
    // {{{ connect()

    /**
     * Connect to a database and log in as the specified user.
     *
     * @param $dsn the data source name (see DB::parseDSN for syntax)
     * @param $persistent (optional) whether the connection should
     *        be persistent
     *
     * @return int DB_OK on success, a DB error code on failure
     */
    function connect($dsninfo, $persistent = false)
    {
        if (!DB::assertExtension('informix') &&
            !DB::assertExtension('Informix'))
        {
            return $this->raiseError(DB_ERROR_EXTENSION_NOT_FOUND);
        }
        $this->dsn = $dsninfo;
        $dbhost = $dsninfo['hostspec'] ? '@' . $dsninfo['hostspec'] : '';
        $dbname = $dsninfo['database'] ? $dsninfo['database'] . $dbhost : '';
        $user = $dsninfo['username'] ? $dsninfo['username'] : '';
        $pw = $dsninfo['password'] ? $dsninfo['password'] : '';

        $connect_function = $persistent ? 'ifx_pconnect' : 'ifx_connect';

        $this->connection = @$connect_function($dbname, $user, $pw);
        if (!is_resource($this->connection)) {
            return $this->ifxraiseError(DB_ERROR_CONNECT_FAILED);
        }
        return DB_OK;
    }

    // }}}
    // {{{ disconnect()

    /**
     * Log out and disconnect from the database.
     *
     * @return bool true on success, false if not connected.
     */
    function disconnect()
    {
        $ret = @ifx_close($this->connection);
        $this->connection = null;
        return $ret;
    }

    // }}}
    // {{{ simpleQuery()

    /**
     * Send a query to Informix and return the results as a
     * Informix resource identifier.
     *
     * @param $query the SQL query
     *
     * @return int returns a valid Informix result for successful SELECT
     * queries, DB_OK for other successful queries.  A DB error code
     * is returned on failure.
     */
    function simpleQuery($query)
    {
        $ismanip = DB::isManip($query);
        $this->last_query = $query;
        $this->affected   = null;
        if (preg_match('/(SELECT)/i', $query)) {    //TESTME: Use !DB::isManip()?
            // the scroll is needed for fetching absolute row numbers
            // in a select query result
            $result = @ifx_query($query, $this->connection, IFX_SCROLL);
        } else {
            if (!$this->autocommit && $ismanip) {
                if ($this->transaction_opcount == 0) {
                    $result = @ifx_query('BEGIN WORK', $this->connection);
                    if (!$result) {
                        return $this->ifxraiseError();
                    }
                }
                $this->transaction_opcount++;
            }
            $result = @ifx_query($query, $this->connection);
        }
        if (!$result) {
            return $this->ifxraiseError();
        }
        $this->affected = @ifx_affected_rows($result);
        // Determine which queries should return data, and which
        // should return an error code only.
        if (preg_match('/(SELECT)/i', $query)) {
            return $result;
        }
        // XXX Testme: free results inside a transaction
        // may cause to stop it and commit the work?

        // Result has to be freed even with a insert or update
        @ifx_free_result($result);

        return DB_OK;
    }

    // }}}
    // {{{ nextResult()

    /**
     * Move the internal ifx result pointer to the next available result
     *
     * @param a valid fbsql result resource
     *
     * @access public
     *
     * @return true if a result is available otherwise return false
     */
    function nextResult($result)
    {
        return false;
    }

    // }}}
    // {{{ affectedRows()

    /**
     * Gets the number of rows affected by the last query.
     * if the last query was a select, returns 0.
     *
     * @return number of rows affected by the last query
     */
    function affectedRows()
    {
        if (DB::isManip($this->last_query)) {
            return $this->affected;
        } else {
            return 0;
        }

    }

    // }}}
    // {{{ fetchInto()

    /**
     * Fetch a row and insert the data into an existing array.
     *
     * Formating of the array and the data therein are configurable.
     * See DB_result::fetchInto() for more information.
     *
     * @param resource $result    query result identifier
     * @param array    $arr       (reference) array where data from the row
     *                            should be placed
     * @param int      $fetchmode how the resulting array should be indexed
     * @param int      $rownum    the row number to fetch
     *
     * @return mixed DB_OK on success, null when end of result set is
     *               reached or on failure
     *
     * @see DB_result::fetchInto()
     * @access private
     */
    function fetchInto($result, &$arr, $fetchmode, $rownum=null)
    {
        if (($rownum !== null) && ($rownum < 0)) {
            return null;
        }
        if ($rownum === null) {
            /*
             * Even though fetch_row() should return the next row  if
             * $rownum is null, it doesn't in all cases.  Bug 598.
             */
            $rownum = 'NEXT';
        } else {
            // Index starts at row 1, unlike most DBMS's starting at 0.
            $rownum++;
        }
        if (!$arr = @ifx_fetch_row($result, $rownum)) {
            return null;
        }
        if ($fetchmode !== DB_FETCHMODE_ASSOC) {
            $i=0;
            $order = array();
            foreach ($arr as $val) {
                $order[$i++] = $val;
            }
            $arr = $order;
        } elseif ($fetchmode == DB_FETCHMODE_ASSOC &&
                  $this->options['portability'] & DB_PORTABILITY_LOWERCASE)
        {
            $arr = array_change_key_case($arr, CASE_LOWER);
        }
        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;
    }

    // }}}
    // {{{ numRows()

    function numRows($result)
    {
        return $this->raiseError(DB_ERROR_NOT_CAPABLE);
    }

    // }}}
    // {{{ numCols()

    /**
     * Get the number of columns in a result set.
     *
     * @param $result Informix result identifier
     *
     * @return int the number of columns per row in $result
     */
    function numCols($result)
    {
        if (!$cols = @ifx_num_fields($result)) {
            return $this->ifxraiseError();
        }
        return $cols;
    }

    // }}}
    // {{{ freeResult()

    /**
     * Free the internal resources associated with $result.
     *
     * @param $result Informix result identifier
     *
     * @return bool true on success, false if $result is invalid
     */
    function freeResult($result)
    {
        return @ifx_free_result($result);
    }

    // }}}
    // {{{ autoCommit()

    /**
     * Enable/disable automatic commits
     */
    function autoCommit($onoff = true)
    {
        // XXX if $this->transaction_opcount > 0, we should probably
        // issue a warning here.
        $this->autocommit = $onoff ? true : false;
        return DB_OK;
    }

    // }}}
    // {{{ commit()

    /**
     * Commit the current transaction.
     */
    function commit()
    {
        if ($this->transaction_opcount > 0) {
            $result = @ifx_query('COMMIT WORK', $this->connection);
            $this->transaction_opcount = 0;
            if (!$result) {
                return $this->ifxRaiseError();
            }
        }
        return DB_OK;
    }

    // }}}
    // {{{ rollback()

    /**
     * Roll back (undo) the current transaction.
     */
    function rollback()
    {
        if ($this->transaction_opcount > 0) {
            $result = @ifx_query('ROLLBACK WORK', $this->connection);
            $this->transaction_opcount = 0;
            if (!$result) {
                return $this->ifxRaiseError();
            }
        }
        return DB_OK;
    }

    // }}}
    // {{{ ifxraiseError()

    /**
     * Gather information about an error, then use that info to create a
     * DB error object and finally return that object.
     *
     * @param  integer  $errno  PEAR error number (usually a DB constant) if
     *                          manually raising an error
     * @return object  DB error object
     * @see errorNative()
     * @see errorCode()
     * @see DB_common::raiseError()
     */
    function ifxraiseError($errno = null)
    {
        if ($errno === null) {
            $errno = $this->errorCode(ifx_error());
        }

        return $this->raiseError($errno, null, null, null,
                            $this->errorNative());
    }

    // }}}
    // {{{ 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  string  $nativecode  error code returned by the database
     * @return int a portable DB error code, or DB_ERROR if this DB
     * implementation has no mapping for the given error code.
     */
    function errorCode($nativecode)
    {
        if (ereg('SQLCODE=(.*)]', $nativecode, $match)) {
            $code = $match[1];
            if (isset($this->errorcode_map[$code])) {
                return $this->errorcode_map[$code];
            }
        }
        return DB_ERROR;
    }

    // }}}
    // {{{ errorNative()

    /**
     * Get the native error message of the last error (if any) that
     * occured on the current connection.
     *
     * @return int native Informix error code
     */
    function errorNative()
    {
        return @ifx_error() . ' ' . @ifx_errormsg();
    }

    // }}}
    // {{{ getSpecialQuery()

    /**
     * Returns the query needed to get some backend info
     * @param string $type What kind of info you want to retrieve
     * @return string The SQL query string
     */
    function getSpecialQuery($type)
    {
        switch ($type) {
            case 'tables':
                return 'select tabname from systables where tabid >= 100';
            default:
                return null;
        }
    }

    // }}}
    // {{{ tableInfo()

    /**
     * Returns information about a table or a result set.
     *
     * NOTE: only supports 'table' if <var>$result</var> is a table name.
     *
     * If analyzing a query result and the result has duplicate field names,
     * an error will be raised saying
     * <samp>can't distinguish duplicate field names</samp>.
     *
     * @param object|string  $result  DB_result object from a query or a
     *                                string containing the name of a table
     * @param int            $mode    a valid tableInfo mode
     * @return array  an associative array with the information requested
     *                or an error object if something is wrong
     * @access public
     * @internal
     * @since 1.6.0
     * @see DB_common::tableInfo()
     */
    function tableInfo($result, $mode = null)
    {
        if (isset($result->result)) {
            /*
             * Probably received a result object.
             * Extract the result resource identifier.
             */
            $id = $result->result;
            $got_string = false;
        } elseif (is_string($result)) {
            /*
             * Probably received a table name.
             * Create a result resource identifier.
             */
            $id = @ifx_query("SELECT * FROM $result WHERE 1=0",
                             $this->connection);
            $got_string = true;
        } else {
            /*
             * Probably received a result resource identifier.
             * Copy it.
             */
            $id = $result;
            $got_string = false;
        }

        if (!is_resource($id)) {
            return $this->ifxRaiseError(DB_ERROR_NEED_MORE_DATA);
        }

        $flds = @ifx_fieldproperties($id);
        $count = @ifx_num_fields($id);

        if (count($flds) != $count) {
            return $this->raiseError("can't distinguish duplicate field names");
        }

        if ($this->options['portability'] & DB_PORTABILITY_LOWERCASE) {
            $case_func = 'strtolower';
        } else {
            $case_func = 'strval';
        }

        $i = 0;
        // made this IF due to performance (one if is faster than $count if's)
        if (!$mode) {
            foreach ($flds as $key => $value) {
                $props = explode(';', $value);

                $res[$i]['table'] = $got_string ? $case_func($result) : '';
                $res[$i]['name']  = $case_func($key);
                $res[$i]['type']  = $props[0];
                $res[$i]['len']   = $props[1];
                $res[$i]['flags'] = $props[4] == 'N' ? 'not_null' : '';
                $i++;
            }

        } else { // full
            $res['num_fields'] = $count;

            foreach ($flds as $key => $value) {
                $props = explode(';', $value);

                $res[$i]['table'] = $got_string ? $case_func($result) : '';
                $res[$i]['name']  = $case_func($key);
                $res[$i]['type']  = $props[0];
                $res[$i]['len']   = $props[1];
                $res[$i]['flags'] = $props[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++;
            }
        }

        // free the result only if we were called on a table
        if ($got_string) {
            @ifx_free_result($id);
        }
        return $res;
    }

    // }}}

}

/*
 * Local variables:
 * tab-width: 4
 * c-basic-offset: 4
 * End:
 */

?>
