Hi Aurélien
Thanks for answering. Please can do read the following : I want to display the numbers of weeks for each student. Each student have one course in a several weeks. i did it the connection by TYPE. documnet 1: student : Name : tom age :31 type: student course: java document 2 : schema 1. cource: java type: course week: 20 2. cource: java type: course week: 22 Now , i want to display the weeks that a student tom have it. the result is week : 20 , 22. How can i do that by using the map function.
