'SET NAMES ' . Config::get(Config::MYSQL_CHARSET))); } } /** * @param int $delta adjust generated timestamp by this value in seconds (either positive or negative) * @return string */ static function NOW(int $delta = 0): string { return date("Y-m-d H:i:s", time() + $delta); } private function __clone() { // } public static function get_dsn(): string { $db_port = Config::get(Config::DB_PORT) ? ';port=' . Config::get(Config::DB_PORT) : ''; $db_host = Config::get(Config::DB_HOST) ? ';host=' . Config::get(Config::DB_HOST) : ''; if (Config::get(Config::DB_TYPE) == "mysql" && Config::get(Config::MYSQL_CHARSET)) { $db_charset = ';charset=' . Config::get(Config::MYSQL_CHARSET); } else { $db_charset = ''; } return Config::get(Config::DB_TYPE) . ':dbname=' . Config::get(Config::DB_NAME) . $db_host . $db_port . $db_charset; } // this really shouldn't be used unless a separate PDO connection is needed // normal usage is Db::pdo()->prepare(...) etc public function pdo_connect() : PDO { try { $pdo = new PDO(self::get_dsn(), Config::get(Config::DB_USER), Config::get(Config::DB_PASS)); } catch (Exception $e) { print "

Exception while creating PDO object:" . $e->getMessage() . "

"; exit(101); } $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); if (Config::get(Config::DB_TYPE) == "pgsql") { $pdo->query("set client_encoding = 'UTF-8'"); $pdo->query("set datestyle = 'ISO, european'"); $pdo->query("set TIME ZONE 0"); $pdo->query("set cpu_tuple_cost = 0.5"); } else if (Config::get(Config::DB_TYPE) == "mysql") { $pdo->query("SET time_zone = '+0:0'"); if (Config::get(Config::MYSQL_CHARSET)) { $pdo->query("SET NAMES " . Config::get(Config::MYSQL_CHARSET)); } } return $pdo; } public static function instance() : Db { if (self::$instance == null) self::$instance = new self(); return self::$instance; } public static function pdo() : PDO { if (self::$instance == null) self::$instance = new self(); if (empty(self::$instance->pdo)) { self::$instance->pdo = self::$instance->pdo_connect(); } return self::$instance->pdo; } public static function sql_random_function(): string { if (Config::get(Config::DB_TYPE) == "mysql") { return "RAND()"; } return "RANDOM()"; } /** * Helper to build a query part comparing a field against a past datetime (determined by "$now - $some_interval") * * The example below could be read as "last_digest_sent is older than 1 day ago". * ```php * Db::past_comparison_qpart('last_digest_sent', '<', 1, 'day'); * ``` * * @todo validate value of $unit and fail if invalid (or massage if practical)? * @link https://www.postgresql.org/docs/current/datatype-datetime.html#DATATYPE-INTERVAL-INPUT * @link https://dev.mysql.com/doc/refman/9.2/en/expressions.html#temporal-intervals * @param string $field the table field being checked * @param '<'|'>'|'<='|'>='|'=' $operator the comparison operator * @param positive-int $quantity the amount of $unit * @param 'year'|'month'|'week'|'day'|'hour'|'minute'|'second' $unit the unit of time for $quantity (see links for more info) * @return string the query part string */ static function past_comparison_qpart(string $field, string $operator, int $quantity, string $unit): string { if (Config::get(Config::DB_TYPE) == 'pgsql') return "$field $operator NOW() - INTERVAL '$quantity $unit' "; return "$field $operator DATE_SUB(NOW(), INTERVAL $quantity $unit) "; } }