MySQL 两列一组

Question

I have a mysql table with the fields id, name, address. Some entries have identical names but different addresses; some have identical addresses but different names.

I want to get a list including one entry at most for each unique address and one entry at most for each unique name.

If I could do a group by name then put the results in a temp table and then select again and do a group by address, then I would get exactly what i want - but that seems too complicated.

And doing a "group by name,address" will not give me what I am looking for - that would include entries for all different combinations of name,address whereas I want one entry for each name and one for each address. Thanks for your help!

Answer 1

There's probably a nicer way to do this, and I'm making some assumptions about what you want, but you could try something like this:

SELECT Name, '' AS Address, Count(Address) AS RowCount
  FROM TableName
  GROUP BY Name
UNION
SELECT '' AS Name, Address, Count(Name) AS RowCount
  FROM TableName
  GROUP BY Address