Question

A hypothetical table contains the following coloumns:

id integer,
name char(6),
status integer

And has the following data:

id    id2     type
---   -----   ----
01    Adam    1
02    Bob     1
03    Adam    2
04    Caymen  1
05    Ahmed   1
06    Basel   1
07    Ahmed   2
08    Bob     2
09    Ahmed   2
10    Mike    1

So it basically tracks status progression for different users.

I want to group on the count of statuses. In other words, I want to know how many users have only 1 status, how many have 2 statuses, how many have 3 statuses, etc.

The expected output would be something like this:

num_of_statuses    count
---------------    -----
1                  3
2                  2
3                  1       

I tried with having, but cannot find a solution yet. Any syntax is OK. SQL/MySQL/DB2/Oracle.

Answer 1

If you don’t feel like using a nested query, you could avoid it like this:

SELECT DISTINCT
  num_of_statuses = COUNT(*),
  count           = COUNT(*) OVER (PARTITION BY COUNT(*))
FROM atable
GROUP BY id