2 db
.createCollection("users")
3 db
.createCollection("courses")
4 db
.createCollection("evaluations")
5 db
.users
.createIndex({ initials: 1, email: 1 }, { unique: true } )
6 db
.courses
.createIndex({ code: 1, uid: 1 }, { unique: true } )
7 db
.evaluations
.createIndex({ cid: 1, name: 1 }, { unique: true } )