Using COUNT in GROUP_CONCAT

Question

This is my table:

  id  | fk_company
-------------------
  1   |     2    
  2   |     2    
  3   |     2    
  4   |     4    
  5   |     4    
  6   |     11          


        

Answer 1

You can also achieve that by counting the number of commas (or whatever's your separator) in the GROUP_CONCAT:

SELECT (LENGTH(GROUP_CONCAT(DISTINCT fk_company))-LENGTH(REPLACE(GROUP_CONCAT(DISTINCT fk_company), ',', '')))
FROM `table`
GROUP BY fk_company