How can I display the most common value sequence in MySQL?

Lets say I have a table like this.

A | B
-----
1 | 4
7 | 8
1 | 3
1 | 2
4 | 5
3 | 5
2 | 5
7 | 8

Even though 1 is the most common value in column A and 5 is the most common value in column B (which can be checked pretty s开发者_运维问答imply with a COUNT()) the result I am looking for is the pair <7, 8> since that pair appears twice.

So how can I get the most common value sequence from a table, since I have n columns that I need to do this with.

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select A, B, count(*) as freq
from MyTable
group by A, B
order by count(*) desc
limit 1