Introducing MongoDB - NoSQL, Document-oriented, JSON Document, Schema-less, MongoDB Shell & Script, CRUD, Schema Design, Query Criteria, Query Operator, Aggregation Pipeline and its Operator and Node.js Driver. All at level 101. 本課程邀請到 Jollen 為大家介紹 MongoDB 與 NoSQL 的基本觀念。NoSQL（Not Only SQL）的簡寫。NoSQL 和傳統的 RDBMS（關聯式資料庫）是很不一樣的技術。MongoDB 搭配 MapReduce 技術，除了是 Big Data 的技術核心，也是資料科學家愛好的技術。

1. Mokoversity
MongoDB & NoSQL 101
2014.9.24
Jollen, Founder
<jollen@jollen.org>
www.mokoversity.com

2. Mokoversity
認識 NoSQL 資料庫

3. NoSQL
• Not Only SQL
• Document-Oriented
• Not a replacement for SQL database
• Schema-less
• Full Text Search, Data-processing, read
faster, write faster
• etc

4. Mokoversity
Document-Oriented 與 JSON

5. Step Zero
$ mongo!
MongoDB shell version: 2.4.2!
...!
> !
> db!
test!
> show dbs!
local! 0.078125GB!
vcard! 0.203125GB!
> use vcard!
switched to db vcard!
>
Cards
mongo
db
showdbs
use

6. 認識 Collections
> use vcard!
switched to db vcard!
> show collections!
messages!
system.indexes!
users!
> exit!
bye
Cards
show collections
exit

7. 什麼是 Collections
• Document Store (aka folder)
• In JSON and BSON format
• aka XML、MS Word、MS Excel
• Grouping documents
• collections
• Directory hierarchies
• Collections could be considered analogous to
tables

8. Key-Value Paris
• Key–Value stores use the associative
array
• The fundamental data model of
document store
• In-memory document store
• Memory Cache
• Redis and etc.

9. Create a new Database
$ mongo!
!
> show dbs!
local! 0.078125GB!
messages! 0.203125GB!
test! 0.203125GB!
> use mytest!
switched to db mytest!
> db.dropDatabase()!
{ "dropped" : "mytest", "ok" : 1 } Cards
use <new-db-name>

10. Save a new Document
> use mytest!
switched to db mytest!
> db.mytest.save({name: 'jollen'})!
> db.mytest.find()!
{ "_id" : ObjectId("53bf7682af97b69f131d970a"), "name" :
"jollen" }!
>
Cards
save()
find()
⾃自動產⽣生

11. 認識 Schema
• NoSQL 資料庫不需要事先定義欄位
• Table Definition
• Document 的欄位定義稱為 Schema
• Has Schema 或 No Schema

12. Query a Collection
• find()
• find({name: ‘Jollen’})
• findOne()

13. Remove a Document
• remove()
• remove({name: 'jollen'})

14. Update a Document
• update({name: 'jollen2'}, {name:
'jollen3'})
• update({name:'jollen'}, {$set: {name:
'jollen2'}}, {multi: true})
Query criteria
fields
New document !
content
http://docs.mongodb.org/manual/reference/method/db.collection.update/

15. 基本的 CRUD 操作
• find()－Read
• Query Criteria
• Projection
• Aggregation
• update()－Update
• Query Criteria

16. 學習要點
• NoSQL 初學者應先學習 Collection 的操作
• CRUD
• 類似於使⽤用 SQL 語法做 Table 的查詢、新增、更新與
刪除
• 學習 Schema Design 觀念與實作
• 學習 Query Criteria
• 學習 Aggregation
• MapReduce 的基礎

17. Query Criteria
• 各式「條件查詢」的做法
• {age: {$gt: 18} }
• WHERE
http://docs.mongodb.org/manual/core/read-operations/

18. Mokoversity
MongoDB CRUD

19. Implement CRUD
• MongoDB Shell
• MongoDB Script
• MongoDB Drivers
• Node.js (JavaScript)
• Python / Ruby
• C / C++
• etc - http://docs.mongodb.org/ecosystem/drivers/

20. MongoDB Script
• 使⽤用 JavaScript 語法
• 進⾏行 CRUD 操作
• 撰寫管理功能
• 簡單的 Data Processing (MapReduce)

21. Create One Document
// 0001!
!
{!
var db = connect('localhost/test');!
!
db.vipData.save({name: 'jollen', tel: '09384567182'});!
!
print('0001-create-one-document finished.')!
}

22. List Collection
// 0002!
!
{!
var db = connect('localhost/test');!
!
db.vipData.find().forEach(function(user) {!
print("User: " + user.name + ", tel: " + user.tel);!
});!
!
print("Info: 0002-list-collection finished.");!
}!

23. Update Document
// 0003!
!
{!
var db = connect('localhost/test');!
!
db.vipData.update({name: 'jollen'}, { $set: {name:
'jollenchen'} });!
!
print('0004-update-document finished');!
}

24. Add News Field
// 0004!
!
{!
var db = connect('localhost/test');!
!
db.vipData.find().forEach(function(data) {!
data.isActive = true;!
db.vipData.save(data);!
});!
!
print('0004-add-new-field finished');!
}

25. Remove Document
// 0005!
!
{!
var db = connect('localhost/test');!
!
db.vipData.remove({name: 'jollen'});!
!
print('0005-remove-document finished.');!
}

26. Mokoversity
Schema Design

27. 基本觀念
• 類似關鍵式資料庫的 Table 設計
• Flexible Schema

28. Schema 設計原則
• When designing data models, always consider
the application usage of the data (i.e. queries,
updates, and processing of the data) as well as
the inherent structure of the data itself.
• There are two tools that allow applications to
represent these relationships: references and
embedded documents.
• References
• Embedded Data
http://docs.mongodb.org/manual/core/data-modeling-introduction/

29. Embedded Document
Post Collection
_id
title
content
tags
Nickname
Fullname
Mobile
Age

30. Reference Model 使⽤用原則
• 亦稱為 Normalized Data Model
• 主要⽤用途
• One-to-Many Relations*
• Many-to-Many Relations
• 主要缺點
• ⽂文件變⼤大時造成 write performance 變差

31. One-To-Many 的情況 #1
{!
_id: "joe",!
name: "Joe Bookreader”,!
address:!
{!
patron_id: "joe",!
street: "123 Fake Street",!
city: "Faketon",!
state: "MA",!
zip: "12345"!
}!
}!
!
{!
_id: "joe",!
name: "Joe Bookreader"!
address:!
{!
patron_id: "joe",!
street: "1 Some Other Street",!
city: "Boston",!
state: "MA",!
zip: “12345"!
}!
}

32. Reference Model
http://docs.mongodb.org/manual/core/data-modeling-introduction/

33. 關於 Reference Model
• 建議使⽤用的 Data Model
• Using references between documents
• Avoid duplication of data
• Provide sufficient read performance advantage

34. Schema Design
User Collection
_id
name
email
address
age Message Collection
_id
message
uid

35. 專案描述
• 將 Microsoft Excel 資料庫，轉換⾄至 NoSQL
的開發任務
• 客⼾戶資料是以 Excel 維護，現在想將客⼾戶資
料「上雲端」，並製作 App 以隨時追蹤或查
詢
• 將客⼾戶資料轉換為 NoSQL 資料庫。以便進
⾏行 RESTful Web Service 的開發，以及 App
的製作

36. CRUD: Task 1
• 建⽴立 vcard 資料庫
• 新增資料⾄至 vcard.users collections
• 資料欄位
• name
• phone
• email
• address
• age

37. 提⽰示
• 將 users.xls 匯⼊入 vcard.users collection
• 註：users.xls 是程式產⽣生的假資料，⾮非真實
資料

38. CRUD: Task 2
• 新增資料⾄至 vcard.messages collections
• 資料欄位
• uid（紀錄 ObjectId）
• message（⽂文章內⽂文）

39. Mokoversity
Aggregation (MapReduce)

40. 使⽤用 Query Criteria
http://docs.mongodb.org/manual/core/crud-introduction/

41. CRUD: Task 3
• 公司想針對 45 歲以下的客⼾戶進⾏行⾏行銷推廣
• 找出 18 歲以上的客⼾戶

42. 使⽤用 Aggregation
exports.query = function(req, res) {!
! var model = req.app.db.models.User;!
!
! model!
! .aggregate([!
{!
! $project: { _id: 1, name: 1, age: 1 }!
},!
{!
! $match: {age: {$gt: 45} }!
},!
{!
! $match: {age: {$lt: 60} }!
}])!
! .exec(function(err, users) {!
! ! res.send(users);!
! ! res.end();!
! });!
}

43. Mokoversity
REST API－Using
Node.js
and mongoose

44. REST API 規劃

45. 認識 CRUD

46. User Collection 的 Schema
// Model name: ‘User’!
var userSchema = new mongoose.Schema({!
name: { type: String, default: ''},!
email: String,!
address: String,!
age: { type: Number, default: 0 }!
});
User Collection
name
email
address
age

47. Message Collection 的 Schema
// Model name: ‘Message’!
var messageSchema = new mongoose.Schema({!
uid: { type: mongoose.Schema.Types.ObjectId, ref: 'User' },!
message: String!
});
Message Collection
_id
message
uid

48. 使⽤用 $in Operator
• 興趣有 ‘sport’ 的會員
{ interests: { $in: [ 'sport' ] } }

49. Populate
model!
.find()!
.populate('uid')!
.exec(function(err, posts) {!
res.send(posts);!
res.end();!
});