show all columns? that would be the dreaded, evil "select star"
i'm not sure, though, what your second question means
you can assign a column alias to the minimum...
SELECT LEAST(col1,col2,col3,col4,col5) AS da_min
however, if you are asking to figure out which of the columns actually contained the minimum, then i must ask you why you need to know this, and why you couldn't figure out everything in your application logic in the first place