query: SELECT product_category ,  count(*) FROM mailshot_campaigns GROUP BY product_category
question: Showing all distinct products category number mailshot each category.
query_toks: SELECT product_category , count ( * ) FROM mailshot_campaigns GROUP BY product_category
query_toks_no_value: select product_category , count ( * ) from mailshot_campaigns group by product_category
question_toks: Showing all distinct products category number mailshot each category.