M102: MongoDB for DBAs chapter 1学习记录

M102: MongoDB for DBAs chapter 1

运行环境

操作系统：windows 10 家庭中文版

Mongodb ：Mongodb 3.4

Mongodb安装路径：E:>MongoDB\Server\3.4\bin\

Mongodb存储路径：E:>MongoDB\data

课后问题

1.1问题

Download and install MongoDB from www.mongodb.org. Then run the database as a single server instance on your PC (that is, run the mongod binary). Then, run the administrative shell.

From the shell prompt type

db.isMaster().maxBsonObjectSize

at the “>” prompt.

What do you get as a result?

Enter answer here:

16777216

解答

mongodb安装方法见我之前的博客：

CentOS7下使用yum安装Mongodb3.4

进入mongo

C:\Users\Shinelon>e:

E:\>MongoDB\Server\3.4\bin\mongo.exe
MongoDB shell version v3.4.6
connecting to: mongodb://127.0.0.1:27017
MongoDB server version: 3.4.6
Server has startup warnings:
2018-03-28T20:01:23.957-0700 I CONTROL  [initandlisten]
2018-03-28T20:01:23.957-0700 I CONTROL  [initandlisten] ** WARNING: Access control is not enabled for the database.
2018-03-28T20:01:23.958-0700 I CONTROL  [initandlisten] **          Read and write access to data and configuration is unrestricted.
2018-03-28T20:01:23.958-0700 I CONTROL  [initandlisten]

执行所给命令

> db.isMaster().maxBsonObjectSize
16777216

这其实是默认的文档大小，即16MB

1.2问题

Download Handouts:

Products__hw1.2_m102_529e39a8e2d42347509fb3f0.json

Download the handout. Take a look at its content.

Now, import its contents into MongoDB, into a database called “pcat” and a collection called “products”. Use the mongoimport utility to do this.

When done, run this query in the mongo shell:

db.products.find( { type : "case" } ).count()

What’s the result?

3

解答

导入所给的Products__hw1.2_m102_529e39a8e2d42347509fb3f0.json文件

C:\Users\Shinelon>e:

E:\>MongoDB\Server\3.4\bin\mongoimport.exe --drop -d pcat -c products C:\Users\Shinelon\Downloads\Products__hw1.2_m102_529e39a8e2d42347509fb3f0.json

进入mongo，并进入pcat库

E:\>MongoDB\Server\3.4\bin\mongo.exe
MongoDB shell version v3.4.6
connecting to: mongodb://127.0.0.1:27017
MongoDB server version: 3.4.6
Server has startup warnings:
2018-03-28T20:01:23.957-0700 I CONTROL  [initandlisten]
2018-03-28T20:01:23.957-0700 I CONTROL  [initandlisten] ** WARNING: Access control is not enabled for the database.
2018-03-28T20:01:23.958-0700 I CONTROL  [initandlisten] **          Read and write access to data and configuration is unrestricted.
2018-03-28T20:01:23.958-0700 I CONTROL  [initandlisten]
> use pcat
switched to db pcat

执行所给查询命令求出结果：

> db.products.find( { type : "case" } ).count()
3

1.3问题

At this point you should have pcat.products loaded from the previous step. You can confirm this by running in the shell:

db.products.find()
// or:
db.products.count()
// should print out "11"

Now, what query would you run to get all the products where brand equals the string “ACME”?

Enter answer here:

db.produ
4000
cts.find({brand:"ACME"})

解答

验证数据库导入正常：

> db.products.find()
{ "_id" : "ac3", "name" : "AC3 Phone", "brand" : "ACME", "type" : "phone", "price" : 200, "warranty_years" : 1, "available" : true }
{ "_id" : "ac7", "name" : "AC7 Phone", "brand" : "ACME", "type" : "phone", "price" : 320, "warranty_years" : 1, "available" : false }
{ "_id" : ObjectId("507d95d5719dbef170f15c00"), "name" : "Phone Service Family Plan", "type" : "service", "monthly_price" : 90, "limits" : { "voice" : { "units" : "minutes", "n" : 1200, "over_rate" : 0.05 }, "data" : { "n" : "unlimited", "over_rate" : 0 }, "sms" : { "n" : "unlimited", "over_rate" : 0.01 } }, "sales_tax" : true, "term_years" : 3, "over_rate" : 0 }
{ "_id" : ObjectId("507d95d5719dbef170f15bff"), "name" : "Phone Service Core Plan", "type" : "service", "monthly_price" : 60, "limits" : { "voice" : { "units" : "minutes", "n" : 1000, "over_rate" : 0.05 }, "data" : { "n" : "unlimited", "over_rate" : 0 }, "sms" : { "n" : "unlimited", "over_rate" : 0 } }, "term_years" : 1 }
{ "_id" : ObjectId("507d95d5719dbef170f15bfb"), "name" : "Phone Extended Warranty", "type" : "warranty", "price" : 38, "warranty_years" : 2, "for" : [ "ac3", "ac7", "ac9", "qp7", "qp8", "qp9" ] }
{ "_id" : ObjectId("507d95d5719dbef170f15bf9"), "name" : "AC3 Series Charger", "type" : [ "accessory", "charger" ], "price" : 19, "warranty_years" : 0.25, "for" : [ "ac3", "ac7", "ac9" ] }
{ "_id" : ObjectId("507d95d5719dbef170f15c01"), "name" : "Cable TV Basic Service Package", "type" : "tv", "monthly_price" : 50, "term_years" : 2, "cancel_penalty" : 25, "sales_tax" : true, "additional_tarriffs" : [ { "kind" : "federal tarriff", "amount" : { "percent_of_service" : 0.06 } }, { "kind" : "misc tarriff", "amount" : 2.25 } ] }
{ "_id" : ObjectId("507d95d5719dbef170f15bfc"), "name" : "AC3 Case Black", "type" : [ "accessory", "case" ], "color" : "black", "price" : 12.5, "warranty_years" : 0.25, "available" : false, "for" : "ac3" }
{ "_id" : ObjectId("507d95d5719dbef170f15bfa"), "name" : "AC3 Case Green", "type" : [ "accessory", "case" ], "color" : "green", "price" : 12, "warranty_years" : 0 }
{ "_id" : ObjectId("507d95d5719dbef170f15bfe"), "name" : "Phone Service Basic Plan", "type" : "service", "monthly_price" : 40, "limits" : { "voice" : { "units" : "minutes", "n" : 400, "over_rate" : 0.05 }, "data" : { "units" : "gigabytes", "n" : 20, "over_rate" : 1 }, "sms" : { "units" : "texts sent", "n" : 100, "over_rate" : 0.001 } }, "term_years" : 2 }
{ "_id" : ObjectId("507d95d5719dbef170f15bfd"), "name" : "AC3 Case Red", "type" : [ "accessory", "case" ], "color" : "red", "price" : 12, "warranty_years" : 0.25, "available" : true, "for" : "ac3" }
> db.products.count()
11

编写并验证查询命令：

> db.products.find({brand:"ACME"})
{ "_id" : "ac3", "name" : "AC3 Phone", "brand" : "ACME", "type" : "phone", "price" : 200, "warranty_years" : 1, "available" : true }
{ "_id" : "ac7", "name" : "AC7 Phone", "brand" : "ACME", "type" : "phone", "price" : 320, "warranty_years" : 1, "available" : false }
{ "_id" : "ac9", "name" : "AC9 Phone", "brand" : "ACME", "type" : "phone", "price" : 333, "warranty_years" : 0.25, "available" : true }

1.4问题

How would you print out, in the shell, just the value in the “name” field, for all the product documents in the collection, without extraneous characters or braces, sorted alphabetically, ascending? (Check all that would apply.)

Check all that apply:

A

db.products.find( { }, { name : 1, _id : 0 } ).sort( { name : 1 } )

B

var c = db.products.find( { }, { name : 1, _id : 0 } ).sort( { name : 1 } );
while( c.hasNext() ) {
print( c.next().name);
}

C

var c = db.products.find( { } ).sort( { name : 1 } );
c.forEach( function( doc ) { print( doc.name ) } );

D

var c = db.products.find( { } ).sort( { name : -1 } );
while( c.hasNext() ) {
print( c.next().name);
}

答案：bc

解答

A

> db.products.find( { }, { name : 1, _id : 0 } ).sort( { name : 1 } )
{ "name" : "AC3 Case Black" }
{ "name" : "AC3 Case Green" }
{ "name" : "AC3 Case Red" }
{ "name" : "AC3 Phone" }
{ "name" : "AC3 Series Charger" }
{ "name" : "AC7 Phone" }
{ "name" : "Cable TV Basic Service Package" }
{ "name" : "Phone Extended Warranty" }
{ "name" : "Phone Service Basic Plan" }
{ "name" : "Phone Service Core Plan" }
{ "name" : "Phone Service Family Plan" }

查询除了所有的字段，且返回格式不符合要求

B

> var c = db.products.find( { }, { name : 1, _id : 0 } ).sort( { name : 1 } );
> while( c.hasNext() ) {
...     print( c.next().name);
... }
AC3 Case Black
AC3 Case Green
AC3 Case Red
AC3 Phone
AC3 Series Charger
AC7 Phone
Cable TV Basic Service Package
Phone Extended Warranty
Phone Service Basic Plan
Phone Service Core Plan
Phone Service Family Plan

符合要求

C

> var c = db.products.find( { } ).sort( { name : 1 } );
> c.forEach( function( doc ) { print( doc.name ) } );
AC3 Case Black
AC3 Case Green
AC3 Case Red
AC3 Phone
AC3 Series Charger
AC7 Phone
Cable TV Basic Service Package
Phone Extended Warranty
Phone Service Basic Plan
Phone Service Core Plan
Phone Service Family Plan

同样符合要求

D

> var c = db.products.find( { } ).sort( { name : -1 } );
> while( c.hasNext() ) {
...     print( c.next().name);
... }
Phone Service Family Plan
Phone Service Core Plan
Phone Service Basic Plan
Phone Extended Warranty
Cable TV Basic Service Package
AC7 Phone
AC3 Series Charger
AC3 Phone
AC3 Case Red
AC3 Case Green
AC3 Case Black

排序反了

所以答案为BC