How to insert in a collection when other collections already exists - mongodb

Question

I am very new to noSQL databases. I have started my journey with mongodb Database in noSQL. Upto today I used mySQL and MS SQL Server. I know how to create tables and relationships between them. But this noSQL concept is totally different than that. So, I am asking this question. I hope I will learn sooner to work with noSQL databases.
I have used the following queries in mongodb to create collections and insert data in it:
db.createCollection('Parties');
db.parties.insert({partyName:"Best Sellers", mobileNo:"9876543214"});
db.parties.insert({partyName:"National Traders", mobileNo:"9876543215"});
db.createCollection('items');
db.items.insert({itemName:"Item-A", size:"12"});
db.items.insert({itemName:"Item-B", size:"8"});
db.createCollection('orders');
Visually my order will have these fields:
Order No : AB/123
Date of Order: 17-06-2016
Party Name : National Traders // It will be a select
Item Name Quantity Rate Amount
--------------------------------------------------------
Item-A //Select 200 20 4000
Item-B //Select 100 30 3000
--------------------------------------------------------
300 7000
My question is:
How can I make a query for mongodb to insert in order collection? I have never used something like nested collections. Can anybosy give me an example??
Update:
Here is the diagram of my database in relational database :
How can I convert it to mongodb style??
Update2:
I have tried to add this code for model order in Node.js:
var mongoose = require('mongoose');
var orderSchema = new mongoose.Schema({
salesOrderId: String,
orderDate: Date,
party: {type: Schema.Types.ObjectId, ref:'Party'},
items:[{{type: Schema.Types.ObjectId, ref:'Item'}, quantity: Number, rate: Number}],
dispatches:{
invoiceId: Number,
dispatchDate: Date,
items: [{{type: Schema.Types.ObjectId, ref:'Item'}, quantity: Number, rate: Number}]
}
});
mongoose.model('Order', orderSchema);

Answer 1

MongoDB doesn't follow the relational database data structure.
Copying the SQL data structure to MongoDB is not the ideal way of using MongoDB. Your application should be modified to work with MongoDB style of data structure.
For storing order data, I would suggest using just one collection which has the entire order data.
{
orderNumber : 7283,
party : {partyName:"Best Sellers", mobileNo:"9876543214"},
items : [
{itemName:"Item-A", size:"12"},
{itemName:"Item-B", size:"8"},
.....
]
orderDate : <>,
total : <>,
status : <>,
.....
}

Answer 2

this problem need three collections:
Item - which will hold item data
Party - which will hold party data
Order which will hold all related data
When order is placed by party, in order collection we are creating document and placing in it some subdocuments:
Order data (id, date, etc)
PartyDetails - as a whole document from party collection
Items - contains an array of all items selected by party with details (Quantity, Rate,etc)
Dispatch and DispatchDetails - those depend of how items are shipped
this structure utilities efficiently document oriented storage, and every time you need to check order status, you need just to ask for one document and you will get subdocuments at one go.
To insert data in such collection will depend of application language you will use, but I think this answer will provide you with power of document database solution.
Any comments welcome!
* EDIT *
var itemToInsertA = db.items.find({"itemName" : "Item-A"}).toArray()
var itemToInsertB = db.items.find({"itemName" : "Item-B"}).toArray()
var party = db.parties.find({"partyName" : "National Traders"}).toArray()
var order = {
//_id - will be assigned by db - but we can do it mannually
orderDate : new Date(), // now
salesOrderId : "Need to provide this from sale now or later",
PartyDetails : party[0],
Items : [{
item : itemToInsertA[0],
Quantity : 200,
Rate : 20,
ValueAtTransactionDate : 4000
}, {
item : itemToInsertB[0],
Quantity : 100,
Rate : 30,
ValueAtTransactionDate : 3000
}
]
}
db.orders.insertOne(order)
so finnaly our order looks like this:
{
"_id" : ObjectId("5767d030ecf8248c30af068c"),
"orderDate" : ISODate("2016-06-20T11:14:56.372Z"),
"salesOrderId" : "Need to provide this from sale now or later",
"PartyDetails" : {
"_id" : ObjectId("5767ce26ecf8248c30af0686"),
"partyName" : "National Traders",
"mobileNo" : "9876543215"
},
"Items" : [
{
"item" : {
"_id" : ObjectId("5767ce26ecf8248c30af0687"),
"itemName" : "Item-A",
"size" : "12"
},
"Quantity" : 200.0,
"Rate" : 20.0,
"ValueAtTransactionDate" : 4000.0
},
{
"item" : {
"_id" : ObjectId("5767ce26ecf8248c30af0688"),
"itemName" : "Item-B",
"size" : "8"
},
"Quantity" : 100.0,
"Rate" : 30.0,
"ValueAtTransactionDate" : 3000.0
}
]
}
to create a diagram I used plantUML with QEditor.
plantumpl dump
#startuml
package "Party"{
[PartyId]
[PartyCode]
[PartyName]
[MobileNumber]
}
package "Item"{
[ItemId]
[ItemCode]
[ItemName]
}
package "Order"{
[OrderId]
[SalesOrderId]
[OrderDate]
node "Dispatch"{
[InvoiceId]
[SalesInvoiceId]
[DateOfDispatch]
}
node "DispatchItemTransaction"{
[DispatchItemTId]
[Quantity.]
[Rate.]
[ItemId.]
[InvoiceId.]
}
component PartyDetails
node "Items"{
component ItemDetails
[Quantity]
[Rate]
[Value]
}
}
Item -> ItemDetails
ItemDetails-->ItemId.
Party -down-> PartyDetails
#enduml