Top n records

Question

I am using MySQL. I am trying to retrieve a set of numbers
that appear in the database the most. I have the following columns,
digit1, digit2, digit3, digit4, digit5, digit6. I am wanting the
top 6 numbers that appear across each column, for an example the
number 17 could show up 5 times in the digit1 column and 6 times in
the digit4 column, in this case it should return a count of 11 for
the number 17. But I only want to see only the top 6 numbers that
could be in any column. Where do I need to start, I can get the top
numbers for each column but not for all the columns together.
TIA

Answer 1

If mySql supports subqueries in the from clause, this will
get you started.
select thenumber, sum(count1) count2
from (
select 'd1' thefield, digit1 thenumber, count(digit1) count1
from yourtable
group by 'd1' digit1
union
select 'd2' thefield, digit2 thenumber, count(digit2) count1
from yourtable
group by 'd2' digit2
etc
) y
group by thenumber
You said you knew how to get the top 6 already, which is
good, because I don't use mySql and wouldn't know that part.