연습문제

CRUD

Insert & Delete

• Insert documents into people (lab2 database).

• Confirm the insertion by db.people.find()

{ “name”: “Kim”, “age”: 21 },
{ “name”: “Lee”, “age”: 22 },
{ “name”: “Jung”, “age”:27},
{ “name”: “Park”, “age”: 27, “skills”: [ “mongodb”, “python”] },
{ “name”: “Choi”, “age”: 22, “score”: 10 }

• Delete a document whose name is Jung.

• Using db.collection_name.remove()

Update

exercise 1

Use the people collection in lab2

• Replace a document that has the name Lee to

  • The name is Lim and the age is 25

• Update a document that has the name Kim, setting age to 20

• Remove the skills field in a document that has the name Park

• Decrease the score field by 2 in a document that has the name Choi

exercise 2

• Insert the document into posts collection in lab3.

  • {"name" : "Lee", "content" : "Hello I'm Lee"}

• Add a comments key containing an array.

  • {"comments" : {"name" : "Kim", "content" : "Good posts.", "votes" : 0}}

• Add multiple comments.

  • {"comments" : {"name" : "Choi", "content" : "How is it going?", "votes" : 1}}

  • {"comments" : {"name" : "David", "content" : "I'm David, What's up?", "votes" : 2}}

  • {"comments" : {"name" : "Jung", "content" : "Glad to hear that", "votes" : 3}}

exercise 3

• Insert the document into users collection in lab3.

  • {"name" : "Joe", "emails" : ["[e-mail]", "[e-mail]", "[e-mail]"]}

• Add other addresses using $addToSet to prevent duplicates.

  • {"emails" : "[e-mail]"}

  • {"emails" : "[e-mail]"}

exercise 4

Use the users collection in lab3.

• Remove first element of joe's emails using $pop.

• Remove the element "[e-mail]" of joe's emails using $pull.

exercise 5

Use the posts collection in lab3.

• Set the votes’ value of the second comment of Lee’s post to 2.

• Set the votes’ value of the Kim’s comment of Lee’s post to 5 using the position operator.

exercise 6

• Insert documents into people in lab3.

  • {"name" : "Kim", "age" : 21, "profile" : "Hello I’m Kim"},

  • {"name" : "Lee", "age" : 22 , "profile" : "Hello I’m Lee"},

  • {"name" : "Jung", "age" : 22 , "profile" : "Hello I'm Jung"},

  • {"name" : "Park", "age" : 26 , "profile" : "Hello I'm Park"}

• Set all the documents’ profile value in people collections to “Your account have been hacked!”

Read

exercise 1

Use the people collection in lab3

• Find the document whose age is 22.

• Find the document whose name is Lee except the profile

exercise 2

Use the people collection in lab3.

• Find the documents whose age is between 22 and 26.

• Find the documents whose name is not Lee.

exercise 3

Use the people collection in lab3

• Find the documents whose name is "Lee" or "Jung".

• Find the documents whose name is not "Kim" or "Park" or "Jung".

exercise 4

Import blog.json into the blog collection in lab4

• Find documents

  • The language includes both Korean and English

• Display a document slicing two comments

  • The document’s title is Big data

exercise 5

Use the blog collection in lab4

• Find a document as following conditions

  • The writer’s first name is Ki

  • The language is Korean

• Find documents that have Kim’s comment

  • Only for an array

  • Regardless of an array

exercise 6

Import sales.json into the sales collection in lab4

• Print all documents using cursor methods

• Sorting amount values in ascending order and then _id in descending order

• Display three documents whose amount is less than 40

• Skip two documents sorted by amount in descending order

• Counting documents whose category of item is Home