includes/Database/Options.php
public function update($name, $newvalue) {
        $name = trim((string)$name);
        if (empty($name)) {
            return false;
        }

        // Use clone to break object refs -- see commit 09b989d375bac65e692277f61a84fede2fb04ae3
        if (is_object($newvalue)) {
            $newvalue = clone $newvalue;
        }

        $oldvalue = yourls_get_option($name);

        // If the new and old values are the same, no need to update.
        if ($newvalue === $oldvalue) {
            return false;
        }

        // If this is a new option, just add it
        if (false === $oldvalue) {
            return $this->add($name, $newvalue);
        }

        $_newvalue = yourls_maybe_serialize($newvalue);
        $table = YOURLS_DB_TABLE_OPTIONS;
        $sql  = "UPDATE $table SET option_value = :value WHERE option_name = :name";
        $bind = array('name' => $name, 'value' => $_newvalue);
        $do   = $this->ydb->fetchAffected($sql, $bind);

        if($do !== 1) {
            // Something went wrong :(
            return false;
        }

        // Cache option value to save a DB query if needed later
        $this->ydb->set_option($name, $newvalue);
    	yourls_do_action( 'update_option', $name, $oldvalue, $newvalue );
        return true;
    }
public function update($name, $newvalue) {
        $name = trim((string)$name);
        if (empty($name)) {
            return false;
        }

        // Use clone to break object refs -- see commit 09b989d375bac65e692277f61a84fede2fb04ae3
        if (is_object($newvalue)) {
            $newvalue = clone $newvalue;
        }

        $oldvalue = yourls_get_option($name);

        // If the new and old values are the same, no need to update.
        if ($newvalue === $oldvalue) {
            return false;
        }

        // If this is a new option, just add it
        if (false === $oldvalue) {
            return $this->add($name, $newvalue);
        }

        $_newvalue = yourls_maybe_serialize($newvalue);
        $table = YOURLS_DB_TABLE_OPTIONS;
        $sql  = "UPDATE $table SET option_value = :value WHERE option_name = :name";
        $bind = array('name' => $name, 'value' => $_newvalue);
        $do   = $this->ydb->fetchAffected($sql, $bind);

        if($do !== 1) {
            // Something went wrong :(
            return false;
        }

        // Cache option value to save a DB query if needed later
        $this->ydb->set_option($name, $newvalue);
    	yourls_do_action( 'update_option', $name, $oldvalue, $newvalue );
        return true;
    }
Update (add if doesn't exist) an option to DB

@since  1.7.3
@param  string $name      Option name. Expected to not be SQL-escaped.
@param  mixed  $newvalue  Option value.
@return bool              False if value was not updated, true otherwise.