如何将总计添加为sql的最后一行？

Question

I'm trying to display a row, 'Total', that will do a sum of the Count column. The following code will have two columns, Environment and Count.

select 
case 
when env is null THEN 'Unknown' 
else env
end,
count(*) as Count
from env_table
group by env
order by env
/

Output I would like:

Windows 200

Linux 120

Total 320

As you can see above, what I would like to do is add a row called "Total" at the end that would essentially do a SUM(count(*)). What is the proper syntax to do this? Thanks!

Answer 1

Use the WITH ROLLUP modifier to GROUP BY :

SELECT   IFNULL(env, 'Unknown'),
         COUNT(*) AS Count
FROM     env_table
GROUP BY env WITH ROLLUP
ORDER BY env

Answer 2

Maybe something like this?

SELECT   IFNULL(env, 'Unknown'),
         COUNT(*) AS Count
FROM env_table
GROUP BY env
ORDER BY env
UNION ALL
SELECT   null,
         Count(*)
FROM env_table

Answer 3

SELECT env, count 
  FROM (SELECT CASE WHEN env is null THEN 'Unknown' ELSE env END env,
               count(*) count
          FROM env_table
         GROUP BY env
      ORDER BY env)
UNION ALL
SELECT 'Total' env,
       count(*) count
  FROM env_table       

Answer 4

SELECT   COALESCE(env, 'Total') AS Description,
         COUNT(*) AS Count
FROM     env_table
GROUP BY env WITH ROLLUP
ORDER BY env