Question

I have two sets of results:

SELECT name, count(appearance) as countA from table where results = '1'
SELECT name, count(appearance) as countB from table where results = '2'

And I wanted to combine them side by side, like this:

+---------+---------+---------+
| col_1   | countA  | countB  |
+---------+---------+---------+
| John    |    3    |    1    |
| Mary    |    1    |    2    |
| Gary    |    2    |   NULL  |
| Sean    |    4    |   NULL  |
| Mike    |  NULL   |    6    |
+---------+---------+---------+

How do I do that?

Answer 1

This should do it (in Oracle) without needing a self join

SELECT name
     , sum( case results when '1' then 1 else 0 end ) as countA 
     , sum( case results when '2' then 1 else 0 end ) as countB
  from table 
 where results IN ( '1', '2' )
 group by
       name