Cursor .foreach and array data - mongodb

Question

I use the cursor .forEach to display the data as a table.
.forEach(function(doc){
print((doc.Id + ';' + doc.item + ';' + doc.delta);
But this does not work with data like this:
items" : [
{
"amount" : 1,
"id" : 158,
}]
How do I bring them to the table using the cursor?
I need something like this:
id-itemId-amount
57 | 158 | 1
58 | 159 | 2
(itemID and amount from array)

Answer 1

The Mongo shell supports standard JavaScript for iterating over an array and the items attribute is an array. So, inside the 'for each function' you can iterate over the items array and print out the id and amount attributes for each subdocment in that array.
For example:
db.collection.find({}).forEach(function(doc) {
// standard JS loop over an array
for (var i in doc.items) {
// print the id from the 'outer' document alongside the id
// and amount from each sub document in the items array
print(doc.id + '|' + doc.items[i].id + '|' + doc.items[i].amount);
}
})
Given the following documents ...
{ "id": 1, items" : [{"amount": 10, "id": 158}, {"amount": 11, "id": 159}]}
{ "id": 2, items" : [{"amount": 20, "id": 266}, {"amount": 21, "id": 267}]}
... the above function will print:
1|10|158
1|11|159
2|20|266
2|21|267