Zabbix

<?php

/*

** Copyright (C) 2001-2025 Zabbix SIA

**

** This program is free software: you can redistribute it and/or modify it under the terms of

** the GNU Affero General Public License as published by the Free Software Foundation, version 3.

**

** This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;

** without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

** See the GNU Affero General Public License for more details.

**

** You should have received a copy of the GNU Affero General Public License along with this program.

** If not, see <https://www.gnu.org/licenses/>.

**/

​

/**

 * Database backend class for MySQL.

 */

class MysqlDbBackend extends DbBackend {

​

    /**

     * Check if 'dbversion' table exists.

     *

     * @return bool

     */

    protected function checkDbVersionTable() {

        $table_exists = DBfetch(DBselect("SHOW TABLES LIKE 'dbversion'"));

​

        if (!$table_exists) {

            $this->setError(_s('Unable to determine current Zabbix database version: %1$s.',

                _s('the table "%1$s" was not found', 'dbversion')

            ));

​

            return false;

        }

​

        return true;

    }

​

    /**

     * Check database and table fields encoding.

     *

     * @return bool

     */

    public function checkEncoding() {

        global $DB;

​

        return $this->checkDatabaseEncoding($DB) && $this->checkTablesEncoding($DB);

    }

​

    /**

     * Check database schema encoding. On error will set warning message.

     *

     * @param array $DB  Array of database settings, same as global $DB.

     *

     * @return bool

     */

    protected function checkDatabaseEncoding(array $DB) {

        $row = DBfetch(DBselect('SELECT default_character_set_name db_charset FROM information_schema.schemata'.

            ' WHERE schema_name='.zbx_dbstr($DB['DATABASE'])

        ));

​

        if ($row && !in_array(strtoupper($row['db_charset']), ZBX_DB_MYSQL_ALLOWED_CHARSETS)) {