[SOLVED] How can I count unique pairs of values in SQL?

How can I count unique pairs of values in SQL?

With the following sql statement I can get all unique values with their counts for a given column:

  select column, 
         count(column) as count 
    from table 
group by column 
order by count desc;

How would I get all unique pairs of values with counts. For instance if I had a table of with columns first_name and last_name, I might find results something like this:

first_name | last_name | count

John | Smith | 42

John | Johnson | 39

David | Smith | 37

etc...

Can I do this in basic SQL? I generally use MySQL, but I assume whatever solution you come up with should be translatable to any db.

Solution

You've almost got it correct... You just add an additional GROUP BY column like so:

SELECT [first_name], [last_name], COUNT(*) AS [Count] 
FROM [Table]
GROUP BY [first_name], [last_name]
ORDER BY [Count] DESC;