Returning unique �cate_id's, as a string separated by the comma(,) in ascending order for each group of 'pub_id' from the book_mast table:

Publisher idGROUP_CONCAT(DISTINCT cate_id)
P003CA001,CA003
P005CA001,CA004
P006CA001,CA005
P001CA002,CA004
P004CA002,CA005
P002CA003
P008CA004,CA005
P007CA005,CA002