I have two tables:

```
users          attributes
id|name        id|name|user_id
-------        ---------------
1 |foo         1 |bla | 1
2 |bar         1 |blub| 1
               1 |bla | 2

```

How do I create a query gives users with both the "bla" AND "blub" attributes?

In this case it should only return the user "foo".

I know that the data is not normalized.