4. mongoDB 데이터 입력/수정/검색/삭제 (CRUD)¶

4.1. Document 입력 - insertOne, insertMany¶

• insertOne : 한개의 document 생성
• insertMany : list of document 생성

Document 입력 문법¶

SQL INSERT 문법과 비교¶

• insertOne 예제

db.articles.insertOne(
     { subject: "coffee", author: "xyz", views: 50 }
)

• insertMany 예제

db.articles.insertMany(
   [
     { subject: "coffee", author: "xyz", views: 50 },
     { subject: "Coffee Shopping", author: "efg", views: 5 },
     { subject: "Baking a cake", author: "abc", views: 90  },
     { subject: "baking", author: "xyz", views: 100 },
     { subject: "Café Con Leche", author: "abc", views: 200 },
     { subject: "Сырники", author: "jkl", views: 80 },
     { subject: "coffee and cream", author: "efg", views: 10 },
     { subject: "Cafe con Leche", author: "xyz", views: 10 },
     { subject: "coffees", author: "xyz", views: 10 },
     { subject: "coffee1", author: "xyz", views: 10 }
   ]
)

4.2. Document 읽기(검색) - findOne, find¶

• findOne : 매칭되는 한개의 document 검색
• find : 매칭되는 list of document 검색

Document 읽기(검색) 문법¶

• find()/findOne 명령과 - SQL 문 비교

db.people.find() - SELECT * FROM people
db.people.find({ }, { user_id: 1, status: 1 }) - SELECT _id, user_id, status FROM people
db.people.find({ },{ user_id: 1, status: 1, _id: 0 }) - SELECT user_id, status FROM people
db.people.find({ status: "A" }) - SELECT * FROM people WHERE status = "A"
db.people.find({ status: "A", age: 50 }) - SELECT * FROM people WHERE status = "A" AND age = 50
db.people.find({ $or: [ { status: "A" } , { age: 50 } ] }) - SELECT * FROM people WHERE status = "A" OR age = 50

비교 문법¶

$eq     =    Matches values that are equal to a specified value.
$gt     >    Matches values that are greater than a specified value.
$gte    >=   Matches values that are greater than or equal to a specified value.
$in          Matches any of the values specified in an array.
$lt     <    Matches values that are less than a specified value.
$lte    <=   Matches values that are less than or equal to a specified value.
$ne     !=   Matches all values that are not equal to a specified value.
$nin         Matches none of the values specified in an array.

비교 문법 코드 예제¶

db.people.find({ age: { $gt: 25 } }) - SELECT * FROM people WHERE age > 25
db.people.find({ age: { $lt: 25 } }) - SELECT * FROM people WHERE age < 25
db.people.find({ age: { $gt: 25, $lte: 50 } }) - SELECT * FROM people WHERE age > 25 AND age <= 50
db.people.find( { user_id: /bc/ } )
db.people.find( { user_id: { $regex: /bc/ } } )
                                                  - SELECT * FROM people WHERE user_id like "%bc%"
db.people.find( { user_id: /^bc/ } )
db.people.find( { user_id: { $regex: /^bc/ } } )
                                                  - SELECT * FROM people WHERE user_id like "bc%"
db.people.find( { status: "A" } ).sort( { user_id: 1 } ) - SELECT * FROM people WHERE status = "A" ORDER BY user_id ASC 
db.people.find( { status: "A" } ).sort( { user_id: -1 } ) - SELECT * FROM people WHERE status = "A" ORDER BY user_id DESC
db.people.count()
db.people.find().count()
                                                  - SELECT COUNT(*) FROM people
db.people.count( { user_id: { $exists: true } } )
db.people.find( { user_id: { $exists: true } } ).count()
                                                  - SELECT COUNT(user_id) FROM people
db.people.count( { age: { $gt: 30 } } )
db.people.find( { age: { $gt: 30 } } ).count()
                                                  - SELECT COUNT(*) FROM people WHERE age > 30
db.people.distinct( "status" ) - SELECT DISTINCT(status) FROM people
db.people.findOne()
db.people.find().limit(1)
                                                  - SELECT * FROM people LIMIT 1

Document 수정 - updateOne, updateMany¶

• updateOne - 매칭되는 한개의 document 업데이트
• updateMany - 매칭되는 list of document 업데이트

4.3. Document 수정 문법¶

Document 수정 코드 예제¶

- db.people.updateMany( { age: { $gt: 25 } }, { $set: { status: "C" } } )
- SQL 변환하면, 
  - UPDATE people SET status = "C" WHERE age > 25
- 한 Document만 수정하려면 updateOne을 사용함
- db.people.updateOne( { age: { $gt: 25 } }, { $set: { status: "C" } } )
- db.people.updateMany( { status: "A" } , { $inc: { age: 3 } } )
- SQL 변환하면,
  - UPDATE people SET age = age + 3 WHERE status = "A"

4.4. Document 삭제 - removeOne, removeMany¶

• removeOne - 매칭되는 한개의 document 삭제
• removeMany - 매칭되는 list of document 삭제

Document 삭제 문법¶

• db.people.deleteMany( { status: "D" } )
• SQL로 변환하면,
  • DELETE FROM people WHERE status = "D"
• db.people.deleteMany({})
• SQL로 변환하면,
  • DELETE FROM people

참고: mongo shell¶

• 로컬에서 서버가 돌아갈 경우,
  • mongo
• 원격 서버에 접속할 경우
  • mongo --host 'host_address' --port 'port'
  • 예) mongo --host 192.10.21.3 --port 27017