Query ( 행 선택 )

💡 https://www.mongodb.com/docs/v4.4/reference/method/db.collection.find/

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전체조회

db.컬렉션명.find(query(행선택), projection(열선택))

db.user.find()

db.user.find({ })

 

 

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조건 지정

 

db.컬렉션명.fing({key:value})

db.user.find({age:56})

 

 

db.user.find({gender:‘f’})

 

 

 

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< 논리 조건 연산자 >

https://www.mongodb.com/docs/manual/reference/operator/query/#logical

 

and 조건지정

• db.컬렉션명.find({key:value, key1:value1})

db.user.find({gender:‘f’, age:18})

 

 

 

• db.컬렉션명.find( { $and:[ { key:value }, { key1:value1 } ] } )

db.user.find({$and:[{gender:‘f’}, {age:18}]})

 

 

 

or 조건 지정

db.컬렉션명.find( { $or:[ { key:value }, { key1:value1 } ] } )

db.user.find({$or:[{gender:‘f’}, {age:56}]})

 

 

 

nor 조건 지정 ⇒ 조건이 모두 false인 경우

db.컬렉션명.find({$nor:[{key:value},{key1:value1}]})

db.user.find({$nor:[{gender:‘f’}, {age:56}]})

 

 

db.user.find({$nor:[{gender:‘f’}, {age:56}]}).count()

 

 

not 조건 지정

db.user.find({age:{$not:{$eq:67}}})

 

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< 비교 조건 연산자 >

https://www.mongodb.com/docs/manual/reference/operator/query/#comparison

 

 

 

$gt 더 큰값 / $lt 더 작은값

db.컬렉션명.find({key:{$gt:value}})

db.user.find({age:{$gt:60}})

 

db.user.find({age:{$gt:40, $lt:60}})           //and 40보다 크고 60보다 작은

 

 

db.user.find({age:{$gt:40, $lt:60}, username:’홍길동’}) //and 40보다 크고 60보다 작고 홍길동인

 

 

 

$in

db.컬렉션명.find({ key: { $in: [v1,v2,..] } })

db.user.find({age:{$in:[34, 67]}})