Select count(*) from result query in MySql?

Question

I need help from you, this is my SQL query:

select count(SID) 
from Test 
where Date = '2012-12-10' 
group by SID

this is my result:

|2|
|3|
|4|
|3|

and now I have to count the results from the first query!

Expected result: 4 

Answer 1

To select count(*) from result query in MySql. you can easily understand, look at this example

select count(*)

from

(

  select count(SID) tot  -- add alias

  from Test 

  where Date = '2010-10-10' 

  group by SID

) src;  -- add alias