distinct should work with the "*" select form
`&&` and `and` are not identical
`a = true and false` results in `a` = `true`
`a = true && false` results in `a` = `false` as intended
in order to achieve the same results with `and` you must indicate
the precedence, e.g. `a = (true and false)` message for your changes. Lines starting
Merge pull request #42 from dannybtran/select-all-vars-distinct

distinct should work with the "*" select form