mysql - SQL Query returning thousands of empty rows -

mysql - SQL Query returning thousands of empty rows -

i have table ~180,000 rows currently. have query:

select `item_id`, count(*) count `user_items` grouping `item_id`

which runs on table columns: 'combination_id', 'user_id' , 'item_id'. there 6000 item_ids , of course of study 180,000 combination_ids mentioned.

i want homecoming number of occurrences of each item_id. when run query in phpmyadmin 180,000 rows in result of empty (as there 6000 or unique item_ids).

could explain why happening?

mysql sql phpmyadmin