class.ilDBPdoMySQL.php

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<?php

declare(strict_types=1);
abstract class ilDBPdoMySQL extends ilDBPdo
{
    protected array $modes = [
        'STRICT_TRANS_TABLES',
        'STRICT_ALL_TABLES',
        'IGNORE_SPACE',
        'NO_ZERO_IN_DATE',
        'NO_ZERO_DATE',
        'ERROR_FOR_DIVISION_BY_ZERO',
        'NO_ENGINE_SUBSTITUTION',
    ];

    public function supportsTransactions(): bool
    {
        return false;
    }

    public function initHelpers(): void
    {
        $this->manager = new ilDBPdoManager($this->pdo, $this);
        $this->reverse = new ilDBPdoReverse($this->pdo, $this);
        $this->field_definition = new ilDBPdoMySQLFieldDefinition($this);
    }

    protected function initSQLMode(): void
    {
        $this->pdo->exec("SET SESSION sql_mode = '" . implode(",", $this->modes) . "';");
    }

    public function supportsEngineMigration(): bool
    {
        return true;
    }

    protected function getAdditionalAttributes(): array
    {
        return array(
            PDO::MYSQL_ATTR_USE_BUFFERED_QUERY => true,
            PDO::ATTR_TIMEOUT => 300 * 60,
        );
    }

    public function migrateTableToEngine(string $table_name, string $engine = ilDBConstants::MYSQL_ENGINE_INNODB): void
    {
        try {
            $this->pdo->exec("ALTER TABLE {$table_name} ENGINE={$engine}");
            if ($this->sequenceExists($table_name)) {
                $this->pdo->exec("ALTER TABLE {$table_name}_seq ENGINE={$engine}");
            }
        } catch (PDOException $e) {
            throw new ilDatabaseException($e->getMessage());
        }
    }

    public function migrateAllTablesToEngine(string $engine = ilDBConstants::MYSQL_ENGINE_INNODB): array
    {
        $engines = $this->queryCol('SHOW ENGINES');
        if (!in_array($engine, $engines, true)) {
            return [];
        }
        $errors = [];
        $tables = $this->listTables();
        array_walk($tables, function (string $table_name) use (&$errors, $engine): void {
            try {
                $this->pdo->exec("ALTER TABLE $table_name ENGINE=$engine");
                if ($this->sequenceExists($table_name)) {
                    $this->pdo->exec("ALTER TABLE {$table_name}_seq ENGINE=$engine");
                }
            } catch (Exception $e) {
                $errors[$table_name] = $e->getMessage();
            }
        });

        return $errors;
    }

    public function migrateTableCollation(
        string $table_name,
        string $collation = ilDBConstants::MYSQL_COLLATION_UTF8MB4
    ): bool {
        $collation_split = explode("_", $collation);
        $character = $collation_split[0] ?? 'utf8mb4';
        $collate = $collation;
        $q = "ALTER TABLE {$this->quoteIdentifier($table_name)} CONVERT TO CHARACTER SET {$character} COLLATE {$collate};";
        try {
            $this->pdo->exec($q);
        } catch (PDOException $e) {
            return false;
        }
        return true;
    }

    public function migrateAllTablesToCollation(string $collation = ilDBConstants::MYSQL_COLLATION_UTF8MB4): array
    {
        $manager = $this->loadModule(ilDBConstants::MODULE_MANAGER);
        $errors = [];
        foreach ($manager->listTables() as $table_name) {
            if (!$this->migrateTableCollation($table_name, $collation)) {
                $errors[] = $table_name;
            }
        }

        return $errors;
    }

    public function supportsCollationMigration(): bool
    {
        return true;
    }

    public function nextId(string $table_name): int
    {
        $sequence_name = $this->quoteIdentifier($this->getSequenceName($table_name), true);
        $seqcol_name = $this->quoteIdentifier('sequence');
        $query = "INSERT INTO $sequence_name ($seqcol_name) VALUES (NULL)";
        try {
            $this->pdo->exec($query);
        } catch (PDOException $e) {
            // no such table check
        }

        $result = $this->query('SELECT LAST_INSERT_ID() AS next');
        $value = $result->fetchObject()->next;

        if (is_numeric($value)) {
            $query = "DELETE FROM $sequence_name WHERE $seqcol_name < $value";
            $this->pdo->exec($query);
        }

        return (int) $value;
    }

    public function doesCollationSupportMB4Strings(): bool
    {
        // Currently ILIAS does not support utf8mb4, after that ilDB could check like this:
        //              static $supported;
        //              if (!isset($supported)) {
        //                      $q = "SELECT default_character_set_name FROM information_schema.SCHEMATA WHERE schema_name = %s;";
        //                      $res = $this->queryF($q, ['text'], [$this->getDbname()]);
        //                      $data = $this->fetchObject($res);
        //                      $supported = ($data->default_character_set_name === 'utf8mb4');
        //              }

        return false;
    }
}