How to find count of multiple columns

Question

How to find count of multiple columns in a table

create table foo (key1 int(11),  key2 int(11) ..)

I would like to do select count() for key1 and count() for key2 from foo in a single query, is it possible?

It will be the same for both, since every row has both columns. — shree.pat18
– shree.pat18, Commented Dec 16, 2014 at 2:45

Gordon Linoff · Accepted Answer · 2014-12-16 02:47:23Z

1

If you want to count the distinct values you can do:

select count(distinct key1), count(distinct key2)
from foo;

If you want counts by values, you can use union all:

select key1, count(*)
from foo
group by key1
union all
select key2, count(*)
from foo
group by key2;

answered Dec 16, 2014 at 2:47

Gordon Linoff

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