db={products:[{"_id":ObjectId("6499d7eb72fb2552774c9f80"),"name":"Product 1","openingStock":10},{"_id":ObjectId("6499d81a72fb2552774c9f82"),"name":"Product 2","openingStock":10},{"_id":ObjectId("6499d83d72fb2552774c9f84"),"name":"Product 3","openingStock":20},{"_id":ObjectId("6499d86e72fb2552774c9f86"),"name":"Product 4","openingStock":15},],sales:[{"_id":ObjectId("64a559f68d79acbc66d96fdf"),"products":[{"product":ObjectId("6499d7eb72fb2552774c9f80"),"qty":3},{"product":ObjectId("6499d83d72fb2552774c9f84"),"qty":3},]},{"_id":ObjectId("64a559da8d79acbc66d96fde"),"products":[{"product":ObjectId("6499d7eb72fb2552774c9f80"),"qty":3},{"product":ObjectId("6499d83d72fb2552774c9f84"),"qty":1.5},]}],purchase:[{"_id":ObjectId("64a5b540ffcbb3b942ccaae8"),"products":[{"product":ObjectId("6499d81a72fb2552774c9f82"),"qty":2},{"product":ObjectId("6499d7eb72fb2552774c9f80"),"qty":3.3}]}]}

db.purchase.find()