Did HW 5

.gitignore

@@ -0,0 +1 @@
+db.py

app.py

@@ -1 +1,57 @@
-# Your DB Code Here
+import pymongo
+import datetime
+from db import * 
+
+db = rhdevsdb
+
+# 1.Number of entries of selling data grouped by isbn
+y = db.books_selling_data.aggregate(
+    [{"$group": { "_id": "$isbn", "count" : {"$sum" : 1}}}]
+    )
+
+print(list(y))
+
+
+#2. For books with more than 15000 total copies sold, return all the titles in a single array
+y = db.books_selling_data.aggregate(
+    [{"$group": { "_id": "$isbn", "total_copies" : {"$sum" : "$copies_sold"}}},
+    {"$match": { "total_copies" : {"$gt" : 15000 }}},
+    {"$lookup": { "from" : "books", "localField": "_id", "foreignField": "isbn", "as":"filtered"}},
+    { "$project" : { "filtered.title" : 1, "_id" : 0 } }
+    ])
+
+print(list(y))
+
+# 3. Find the number of books by John Doe, sorted by isbn (but isbn is not returned)
+
+y = db.books.aggregate(
+    [{"$group": { "_id": "$isbn", "author" : { "$push" : "$author" }, "title" : { "$push" : "$title" }}},
+    {"$match" : { "author" : "John Doe"}},
+    { "$sort": { "_id": 1}},
+    { "$project" : { "title" : 1, "_id" : 0 }},
+    ])
+
+print(list(y))
+
+
+#4. Return the price per book for each order
+
+y = db.books_selling_data.aggregate(
+    [{"$addFields" : {"price_per_book ": {"$divide": ["$total_price", "$copies_sold"]}}},
+    {"$project" : { "order_id" : 1, "price_per_book" : 1 }}
+    ])
+
+print(list(y))
+
+
+#5. Return the average price per book for each order supplied from titan
+
+y = db.books_selling_data.aggregate(
+    [{"$addFields" : {"price_per_book ": {"$divide": ["$total_price", "$copies_sold"]}}},
+    { "$unwind" : "$supplier"},
+    { "$match" : { "supplier" : "titan"}},
+    {"$group":{"_id":"$supplier", "average price per book": {"$avg": "$price per book"}}}
+    ])
+
+print(list(y))
+