<?php
require_once('common.php');

// vim ts=4:sw=4:et
# Note: run with upgrade.php?debug=1 to see all SQL error messages


/** 
 * Use this to check whether an object (Table, index etc) exists within a 
 * PostgreSQL database.
 * @param String the object name
 * @return boolean true if it exists
 */
function _pgsql_object_exists($name) {
    $sql = "select relname from pg_class where relname = '$name'";
    $r = db_query($sql);
    if($r['rows'] == 1) {
        return true;
    }
    return false;
}

function _pgsql_field_exists($table, $field) {
    $sql = '
    SELECT
        a.attname,
        pg_catalog.format_type(a.atttypid, a.atttypmod) AS "Datatype"
    FROM
        pg_catalog.pg_attribute a
    WHERE
        a.attnum > 0
        AND NOT a.attisdropped
        AND a.attrelid = (
            SELECT c.oid
            FROM pg_catalog.pg_class c
                LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
            WHERE c.relname ~ ' . "'^($table)\$' 
                AND pg_catalog.pg_table_is_visible(c.oid)
        )
        AND a.attname = '$field' ";
//    echo $sql;
    $r = db_query($sql);
    $row = db_row($r['result']);
    if($row) {
        return true;
    }
    return false;
}


if($CONF['database_type'] == 'pgsql') {
    // check if table already exists, if so, don't recreate it
    $r = db_query("SELECT relname FROM pg_class WHERE relname = 'config'");
    if($r['rows'] == 0) {
        $pgsql = "
            CREATE TABLE config ( 
                    id SERIAL,
                    name VARCHAR(20) NOT NULL UNIQUE,
                    value VARCHAR(20) NOT NULL,
                    PRIMARY KEY(id)
                    )";
        db_query_parsed($pgsql);
    }
}
else {
    $mysql = "
        CREATE TABLE {IF_NOT_EXISTS} " . table_by_key ('config') . "(
        `id` {AUTOINCREMENT} {PRIMARY},
        `name`  VARCHAR(20) {LATIN1} NOT NULL DEFAULT '',
        `value` VARCHAR(20) {LATIN1} NOT NULL DEFAULT '',
        UNIQUE name ( `name` )
            )
            ";
    db_query_parsed($mysql, 0, " ENGINE = MYISAM COMMENT = 'PostfixAdmin settings'");
}

$sql = "SELECT * FROM config WHERE name = 'version'";

// insert into config('version', '01');

$r = db_query($sql);

if($r['rows'] == 1) {
    $rs = $r['result'];
    $row = db_array($rs);
    $version = $row['value'];
} else {
    $version = 0;
}

_do_upgrade($version);


function _do_upgrade($current_version) {
    global $CONF;
    $target_version = preg_replace('/[^0-9]/', '', '$Revision$');

    if ($current_version >= $target_version) {
# already up to date
        echo "up to date";
        return true;
    }

    echo "<p>Updating database:<p>old version: $current_version; target version: $target_version";

    for ($i = $current_version +1; $i <= $target_version; $i++) {
        $function = "upgrade_$i";
        $function_mysql = $function . "_mysql";
        $function_pgsql = $function . "_pgsql";
        if (function_exists($function)) {
            echo "<p>updating to version $i (all databases)...";
            $function();
            echo " &nbsp; done";
        }
        if ($CONF['database_type'] == 'mysql' || $CONF['database_type'] == 'mysqli' ) {
            if (function_exists($function_mysql)) {
                echo "<p>updating to version $i (MySQL)...";
                $function_mysql();
                echo " &nbsp; done";
            }
        } elseif($CONF['database_type'] == 'pgsql') {
            if (function_exists($function_pgsql)) {
                echo "<p>updating to version $i (PgSQL)...";
                $function_pgsql();
                echo " &nbsp; done";
            }
        } 
        // Update config table so we don't run the same query twice in the future.
        $i = (int) $i;
        $sql = "UPDATE config SET value = $i WHERE name = 'version'";
        db_query($sql);
    };
}

/**
 * Replaces database specific parts in a query
 * @param String sql query with placeholders
 * @param int (optional) whether errors should be ignored (0=false)
 * @param String (optional) MySQL specific code to attach, useful for COMMENT= on CREATE TABLE
 * @return String sql query
 */ 

function db_query_parsed($sql, $ignore_errors = 0, $attach_mysql = "") {
    global $CONF;

    if ($CONF['database_type'] == 'mysql' || $CONF['database_type'] == 'mysqli' ) {

        $replace = array(
                '{AUTOINCREMENT}'   => 'int(11) not null auto_increment', 
                '{PRIMARY}'         => 'primary key',
                '{UNSIGNED}'        => 'unsigned'  , 
                '{FULLTEXT}'        => 'FULLTEXT', 
                '{BOOLEAN}'         => 'tinyint(1) NOT NULL',
                '{UTF-8}'           => '/*!40100 CHARACTER SET utf8 COLLATE utf8_unicode_ci */',
                '{LATIN1}'          => '/*!40100 CHARACTER SET latin1 COLLATE latin1_swedish_ci */',
                '{IF_NOT_EXISTS}'   => 'IF NOT EXISTS',
                '{RENAME_COLUMN}'   => 'CHANGE COLUMN',
                );
        $sql = "$sql $attach_mysql";

    } elseif($CONF['database_type'] == 'pgsql') {
        $replace = array(
                '{AUTOINCREMENT}'   => 'SERIAL', 
                '{PRIMARY}'         => 'primary key', 
                '{UNSIGNED}'        => '', 
                '{FULLTEXT}'        => '', 
                '{BOOLEAN}'         => 'BOOLEAN NOT NULL', 
                '{UTF-8}'           => '', # TODO: UTF-8 is simply ignored.
                '{LATIN1}'          => '', # TODO: same for latin1 
                '{IF_NOT_EXISTS}'   => '', # TODO: does this work with PgSQL? NO
                '{RENAME_COLUMN}'   => 'ALTER COLUMN', # PgSQL : ALTER TABLE x RENAME x TO y
                'int(1)'            => 'int',
                'int(10)'           => 'int', 
                'int(11)'           => 'int', 
                'int(4)'            => 'int', 
                );

    } else {
        echo "Sorry, unsupported database type " . $conf['database_type'];
        exit;
    }

    $replace['{BOOL_TRUE}'] = db_get_boolean(True);
    $replace['{BOOL_FALSE}'] = db_get_boolean(False);

    $query = trim(str_replace(array_keys($replace), $replace, $sql));
    $result = db_query($query, $ignore_errors);
    if (safeget('debug') != "") {
        print "<p style='color:#999'>$query";
        print "<div style='color:#f00'>" . $result['error'] . "</div>";
    }
    return $result;
}

function _drop_index ($table, $index) {
    global $CONF;
    $tabe = table_by_key ($table);

    if ($CONF['database_type'] == 'mysql' || $CONF['database_type'] == 'mysqli' ) {
        return "ALTER TABLE $table DROP INDEX $index";
    } elseif($CONF['database_type'] == 'pgsql') {
        return "DROP INDEX $index"; # Index names are unique with a DB for PostgreSQL
    } else {
        echo "Sorry, unsupported database type " . $conf['database_type'];
        exit;
    }
}

function upgrade_1() {
# inserting the version number is a good start ;-)
    db_insert(
            'config', 
            array(
                'name' => 'version',
                'value' => '1',
                )
            );
    echo "upgrade_1";
}

function upgrade_2_mysql() {
# upgrade pre-2.1 database
# from TABLE_BACKUP_MX.TXT
    $table_domain = table_by_key ('domain');
    $result = db_query_parsed("ALTER TABLE $table_domain ADD COLUMN transport VARCHAR(255) AFTER maxquota;", TRUE);
    // don't think PGSQL supports 'AFTER transport'
    $result = db_query_parsed("ALTER TABLE $table_domain ADD COLUMN backupmx {BOOLEAN} DEFAULT {BOOL_FALSE} AFTER transport;", TRUE);
    # possible errors that can be ignored:
    # - Invalid query: Table 'postfix.domain' doesn't exist
}

function upgrade_2_pgsql() {
    $table_domain = table_by_key ('domain');
    $result = db_query_parsed("ALTER TABLE $table_domain ADD COLUMN transport VARCHAR(255)", TRUE);
    $result = db_query_parsed("ALTER TABLE $table_domain ADD COLUMN backupmx BOOLEAN DEFAULT false", TRUE);
}

function upgrade_3_mysql() {
# upgrade pre-2.1 database
# from TABLE_CHANGES.TXT
    $table_admin = table_by_key ('admin');
    $table_alias = table_by_key ('alias');
    $table_domain = table_by_key ('domain');
    $table_mailbox = table_by_key ('mailbox');
    $table_vacation = table_by_key ('vacation');

    // these will not work on PostgreSQL; syntax is :
    // ALTER TABLE foo RENAME f1 TO f2 
    $all_sql = split("\n", trim("
                ALTER TABLE $table_admin {RENAME_COLUMN} create_date created DATETIME DEFAULT '0000-00-00 00:00:00' NOT NULL;
                ALTER TABLE $table_admin {RENAME_COLUMN} change_date modified DATETIME DEFAULT '0000-00-00 00:00:00' NOT NULL;
                ALTER TABLE $table_alias {RENAME_COLUMN} create_date created DATETIME DEFAULT '0000-00-00 00:00:00' NOT NULL;
                ALTER TABLE $table_alias {RENAME_COLUMN} change_date modified DATETIME DEFAULT '0000-00-00 00:00:00' NOT NULL;
                ALTER TABLE $table_domain {RENAME_COLUMN} create_date created DATETIME DEFAULT '0000-00-00 00:00:00' NOT NULL;
                ALTER TABLE $table_domain {RENAME_COLUMN} change_date modified DATETIME DEFAULT '0000-00-00 00:00:00' NOT NULL;
                ALTER TABLE $table_domain ADD COLUMN aliases INT(10) DEFAULT '-1' NOT NULL AFTER description;
                ALTER TABLE $table_domain ADD COLUMN mailboxes INT(10) DEFAULT '-1' NOT NULL AFTER aliases;
                ALTER TABLE $table_domain ADD COLUMN maxquota INT(10) DEFAULT '-1' NOT NULL AFTER mailboxes;
                ALTER TABLE $table_domain ADD COLUMN transport VARCHAR(255) AFTER maxquota;
                ALTER TABLE $table_domain ADD COLUMN backupmx TINYINT(1) DEFAULT '0' NOT NULL AFTER transport;
                ALTER TABLE $table_mailbox {RENAME_COLUMN} create_date created DATETIME DEFAULT '0000-00-00 00:00:00' NOT NULL;
                ALTER TABLE $table_mailbox {RENAME_COLUMN} change_date modified DATETIME DEFAULT '0000-00-00 00:00:00' NOT NULL;
                ALTER TABLE $table_mailbox ADD COLUMN quota INT(10) DEFAULT '-1' NOT NULL AFTER maildir;
                ALTER TABLE $table_vacation ADD COLUMN domain VARCHAR(255) DEFAULT '' NOT NULL AFTER cache;
                ALTER TABLE $table_vacation ADD COLUMN created DATETIME DEFAULT '0000-00-00 00:00:00' NOT NULL AFTER domain;
                ALTER TABLE $table_vacation ADD COLUMN active TINYINT(1) DEFAULT '1' NOT NULL AFTER created;
                ALTER TABLE $table_vacation DROP PRIMARY KEY
                ALTER TABLE $table_vacation ADD PRIMARY KEY(email)
                UPDATE $table_vacation SET domain=SUBSTRING_INDEX(email, '@', -1) WHERE email=email;
    "));

    foreach ($all_sql as $sql) {
        $result = db_query_parsed($sql, TRUE);
    }
    # Possible errors that can be ignored:
    # - Invalid query: Table 'postfix.*' doesn't exist
}

function upgrade_4_mysql() { # MySQL only
# changes between 2.1 and moving to sourceforge
    $table_domain = table_by_key ('domain');
    $result = db_query_parsed("ALTER TABLE $table_domain ADD COLUMN quota int(10) NOT NULL default '0' AFTER maxquota", TRUE);
    # Possible errors that can be ignored:
    # - Invalid query: Table 'postfix.domain' doesn't exist
}

/**
 * Changes between 2.1 and moving to sf.net
 */
function upgrade_4_pgsql() { 
    $table_domain = table_by_key('domain');
    $table_admin = table_by_key('admin');
    $table_alias = table_by_key('alias');
    $table_domain_admins = table_by_key('domain_admins');
    $table_log = table_by_key('log');
    $table_mailbox = table_by_key('mailbox');
    $table_vacation = table_by_key('vacation');

    if(!_pgsql_field_exists($table_domain, 'quota')) {
        $result = db_query_parsed("ALTER TABLE $table_domain ADD COLUMN quota int NOT NULL default '0'");
    }

    $result = db_query_parsed("ALTER TABLE $table_domain ALTER COLUMN domain DROP DEFAULT");
    if(!_pgsql_object_exists('domain_domain_active')) {
        $result = db_query_parsed("CREATE INDEX domain_domain_active ON domain(domain,active)");
    }
    
    $result = db_query_parsed("ALTER TABLE $table_domain_admins ALTER COLUMN domain DROP DEFAULT");
    $result = db_query_parsed("ALTER TABLE $table_alias ALTER COLUMN address DROP DEFAULT");
    $result = db_query_parsed("ALTER TABLE $table_alias ALTER COLUMN domain DROP DEFAULT");
    if(!_pgsql_object_exists('alias_address_active')) {
        $result = db_query_parsed("CREATE INDEX alias_address_active ON alias(address,active)");
    }


    $result = db_query_parsed("ALTER TABLE $table_domain_admins ALTER COLUMN username DROP DEFAULT");
    $result = db_query_parsed("ALTER TABLE $table_domain_admins ALTER COLUMN domain DROP DEFAULT");

    $result = db_query_parsed("
        BEGIN;
            ALTER TABLE $table_log RENAME COLUMN data TO data_old;
            ALTER TABLE $table_log ADD COLUMN data text NOT NULL default '';
            UPDATE $table_log SET data = CAST(data_old AS text);
            ALTER TABLE $table_log DROP COLUMN data_old;
        COMMIT;");

    $result = db_query_parsed("ALTER TABLE $table_mailbox ALTER COLUMN username DROP DEFAULT");
    $result = db_query_parsed("ALTER TABLE $table_mailbox ALTER COLUMN domain DROP DEFAULT");

    $result = db_query_parsed("
        BEGIN;
        ALTER TABLE $table_mailbox RENAME COLUMN domain TO domain_old;
        ALTER TABLE $table_mailbox ADD COLUMN domain varchar(255) REFERENCES domain (domain);
        UPDATE $table_mailbox SET domain = domain_old;
        ALTER TABLE $table_mailbox DROP COLUMN domain_old;
        COMMIT;"
        );
    if(!_pgsql_object_exists('mailbox_username_active')) {
        db_query_parsed('CREATE INDEX mailbox_username_active ON mailbox(username,active)');
    }


    $result = db_query_parsed("ALTER TABLE $table_vacation ALTER COLUMN body SET DEFAULT ''");
    if(_pgsql_field_exists($table_vacation, 'cache')) {
        $result = db_query_parsed("ALTER TABLE $table_vacation DROP COLUMN cache");
    }

    $result = db_query_parsed("
        BEGIN;
        ALTER TABLE $table_vacation RENAME COLUMN domain to domain_old;
        ALTER TABLE $table_vacation ADD COLUMN domain varchar(255) REFERENCES domain;
        UPDATE $table_vacation SET domain = domain_old;
        ALTER TABLE $table_vacation DROP COLUMN domain_old;
        COMMIT;
        ");

    if(!_pgsql_object_exists('vacation_email_active')) {
        $result = db_query_parsed("CREATE INDEX vacation_email_active ON vacation(email,active)");
    }

    if(!_pgsql_object_exists('vacation_notification')) {
        $result = db_query_parsed("
            CREATE TABLE vacation_notification (
            on_vacation character varying(255) NOT NULL REFERENCES vacation(email) ON DELETE CASCADE,
            notified character varying(255) NOT NULL,
            notified_at timestamp with time zone NOT NULL DEFAULT now(),
            CONSTRAINT vacation_notification_pkey primary key(on_vacation,notified)
        );");
    }
}

/**
 * create tables
 * version: Sourceforge SVN r1 of DATABASE_MYSQL.txt
 * changes compared to DATABASE_MYSQL.txt:
 * - removed MySQL user and database creation
 * - removed creation of default superadmin
 */
function upgrade_5_mysql() {

    $result = db_query_parsed("
        CREATE TABLE {IF_NOT_EXISTS} `" . table_by_key('admin') . "` (
          `username` varchar(255) NOT NULL default '',
          `password` varchar(255) NOT NULL default '',
          `created` datetime NOT NULL default '0000-00-00 00:00:00',
          `modified` datetime NOT NULL default '0000-00-00 00:00:00',
          `active` tinyint(1) NOT NULL default '1',
          PRIMARY KEY  (`username`),
          KEY username (`username`)
        ) TYPE=MyISAM COMMENT='Postfix Admin - Virtual Admins';
    ");

    $result = db_query_parsed("
        CREATE TABLE {IF_NOT_EXISTS} `" . table_by_key('alias') . "` (
          `address` varchar(255) NOT NULL default '',
          `goto` text NOT NULL,
          `domain` varchar(255) NOT NULL default '',
          `created` datetime NOT NULL default '0000-00-00 00:00:00',
          `modified` datetime NOT NULL default '0000-00-00 00:00:00',
          `active` tinyint(1) NOT NULL default '1',
          PRIMARY KEY  (`address`),
          KEY address (`address`)
        ) TYPE=MyISAM COMMENT='Postfix Admin - Virtual Aliases';
    ");

    $result = db_query_parsed("
        CREATE TABLE {IF_NOT_EXISTS} `" . table_by_key('domain') . "` (
          `domain` varchar(255) NOT NULL default '',
          `description` varchar(255) NOT NULL default '',
          `aliases` int(10) NOT NULL default '0',
          `mailboxes` int(10) NOT NULL default '0',
          `maxquota` int(10) NOT NULL default '0',
          `quota` int(10) NOT NULL default '0',
          `transport` varchar(255) default NULL,
          `backupmx` tinyint(1) NOT NULL default '0',
          `created` datetime NOT NULL default '0000-00-00 00:00:00',
          `modified` datetime NOT NULL default '0000-00-00 00:00:00',
          `active` tinyint(1) NOT NULL default '1',
          PRIMARY KEY  (`domain`),
          KEY domain (`domain`)
        ) TYPE=MyISAM COMMENT='Postfix Admin - Virtual Domains';
    ");

    $result = db_query_parsed("
        CREATE TABLE {IF_NOT_EXISTS} `" . table_by_key('domain_admins') . "` (
          `username` varchar(255) NOT NULL default '',
          `domain` varchar(255) NOT NULL default '',
          `created` datetime NOT NULL default '0000-00-00 00:00:00',
          `active` tinyint(1) NOT NULL default '1',
          KEY username (`username`)
        ) TYPE=MyISAM COMMENT='Postfix Admin - Domain Admins';
    ");

    $result = db_query_parsed("
        CREATE TABLE {IF_NOT_EXISTS} `" . table_by_key('log') . "` (
          `timestamp` datetime NOT NULL default '0000-00-00 00:00:00',
          `username` varchar(255) NOT NULL default '',
          `domain` varchar(255) NOT NULL default '',
          `action` varchar(255) NOT NULL default '',
          `data` varchar(255) NOT NULL default '',
          KEY timestamp (`timestamp`)
        ) TYPE=MyISAM COMMENT='Postfix Admin - Log';
    ");

    $result = db_query_parsed("
        CREATE TABLE {IF_NOT_EXISTS} `" . table_by_key('mailbox') . "` (
          `username` varchar(255) NOT NULL default '',
          `password` varchar(255) NOT NULL default '',
          `name` varchar(255) NOT NULL default '',
          `maildir` varchar(255) NOT NULL default '',
          `quota` int(10) NOT NULL default '0',
          `domain` varchar(255) NOT NULL default '',
          `created` datetime NOT NULL default '0000-00-00 00:00:00',
          `modified` datetime NOT NULL default '0000-00-00 00:00:00',
          `active` tinyint(1) NOT NULL default '1',
          PRIMARY KEY  (`username`),
          KEY username (`username`)
        ) TYPE=MyISAM COMMENT='Postfix Admin - Virtual Mailboxes';
    ");

    $result = db_query_parsed("
        CREATE TABLE {IF_NOT_EXISTS} `" . table_by_key('vacation') . "` (
          `email` varchar(255) NOT NULL default '',
          `subject` varchar(255) NOT NULL default '',
          `body` text NOT NULL default '',
          `cache` text NOT NULL default '',
          `domain` varchar(255) NOT NULL default '',
          `created` datetime NOT NULL default '0000-00-00 00:00:00',
          `active` tinyint(1) NOT NULL default '1',
          PRIMARY KEY  (`email`),
          KEY email (`email`)
        ) TYPE=MyISAM COMMENT='Postfix Admin - Virtual Vacation';
    ");
    # Possible errors that can be ignored:
    # - (none)
}

/**
 * drop useless indicies (already available as primary key)
 */
function upgrade_79_mysql() { # MySQL only
    $result = db_query_parsed(_drop_index('admin', 'username'), True);
    $result = db_query_parsed(_drop_index('alias', 'address'), True);
    $result = db_query_parsed(_drop_index('domain', 'domain'), True);
    $result = db_query_parsed(_drop_index('mailbox', 'username'), True);
}

function upgrade_81_mysql() { # MySQL only
    $table_vacation = table_by_key ('vacation');
    $table_vacation_notification = table_by_key('vacation_notification');

    $all_sql = split("\n", trim("
                ALTER TABLE `$table_vacation` CHANGE `email`    `email`   VARCHAR( 255 ) {LATIN1} NOT NULL
                ALTER TABLE `$table_vacation` CHANGE `subject`  `subject` VARCHAR( 255 ) {UTF-8}  NOT NULL
                ALTER TABLE `$table_vacation` CHANGE `body`     `body`    TEXT           {UTF-8}  NOT NULL
                ALTER TABLE `$table_vacation` CHANGE `cache`    `cache`   TEXT           {LATIN1} NOT NULL
                ALTER TABLE `$table_vacation` CHANGE `domain`   `domain`  VARCHAR( 255 ) {LATIN1} NOT NULL
                ALTER TABLE `$table_vacation` CHANGE `active`   `active`  TINYINT( 1 )            NOT NULL DEFAULT '1'
                ALTER TABLE `$table_vacation` DEFAULT                                    {LATIN1}
                ALTER TABLE `$table_vacation` ENGINE = INNODB
                "));

    foreach ($all_sql as $sql) {
        $result = db_query_parsed($sql, TRUE);
    }

    db_query_parsed(
            "   CREATE TABLE {IF_NOT_EXISTS} $table_vacation_notification (
        on_vacation varchar(255) NOT NULL,
                    notified varchar(255) NOT NULL,
                    notified_at timestamp NOT NULL default now(),
                    CONSTRAINT vacation_notification_pkey PRIMARY KEY(on_vacation, notified),
                    FOREIGN KEY (on_vacation) REFERENCES vacation(email) ON DELETE CASCADE
                        )
            ", 
            TRUE, 
            "   ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_general_ci TYPE=InnoDB 
            COMMENT='Postfix Admin - Virtual Vacation Notifications'
            "
            );
}

/**
 * Make logging translatable - i.e. create alias => create_alias
 */
function upgrade_90() {
    $result = db_query_parsed("UPDATE " . table_by_key ('log') . " SET action = REPLACE(action,' ','_')", TRUE);
    # change edit_alias_state to edit_alias_active
    $result = db_query_parsed("UPDATE " . table_by_key ('log') . " SET action = 'edit_alias_state' WHERE action = 'edit_alias_active'", TRUE);
}

/**
 * MySQL only allow quota > 2 GB
 */
function upgrade_169_mysql() { 

    $table_domain = table_by_key ('domain');
    $table_mailbox = table_by_key ('mailbox');
    $result = db_query_parsed("ALTER TABLE $table_domain MODIFY COLUMN `quota` bigint(20) NOT NULL default '0'", TRUE);
    $result = db_query_parsed("ALTER TABLE $table_domain MODIFY COLUMN `maxquota` bigint(20) NOT NULL default '0'", TRUE);
    $result = db_query_parsed("ALTER TABLE $table_mailbox MODIFY COLUMN `quota` bigint(20) NOT NULL default '0'", TRUE);
}


/*
   TODO

   Database changes that should be done:
   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

MySQL:
 * vacation: 
 - DROP INDEX email
 - 'cache' field might be obsolete with vacation_notification - needs to be checked!
 * vacation_notification:
 - DEFAULT CHARSET and COLLATE should be changed
 - change all varchar fields to latin1 (email addresses don't contain utf8 characters)
* charset of equal fields MUST be the same (see bugreport)
* if necessary, delete the CONSTRAINT before changing field type and create it again
  http://dev.mysql.com/doc/refman/5.0/en/innodb-foreign-key-constraints.html
 */