Doctrine/DBAL/Driver/PDODblib/Driver.php
public function constructPdoDsn(array $params)
    {
        if (PlatformHelper::isWindows()) {
            return $this->constructPdoDsnWindows($params);
        }
        return $this->constructPdoDsnUnix($params);
    }
public function constructPdoDsn(array $params)
    {
        if (PlatformHelper::isWindows()) {
            return $this->constructPdoDsnWindows($params);
        }
        return $this->constructPdoDsnUnix($params);
    }
Constructs the Dblib PDO DSN.

@return string  The DSN.