[MongoDB] Query and Projection Operators | 쿼리 연산자 및 프로젝션 연산자

Query and Projection Operators

쿼리 연산자 및 프로젝션 연산자

- Query Operator는 DB 내에서 데이터를 검색하는 연산자이고,
  Projection Operator는 데이터의 출력 방식을 조작하는 연산자이다.

---

Query Selectors (쿼리 셀렉터, 쿼리 연산자)

Comparison (비교 연산자)

For comparison of different BSON type values, see the specified BSON comparison order.

Name	Syntax	Description
$eq	{ <field>: { $eq: <value> } }	동등 연산 (=)
$ne	{ <field>: { $ne: <value> } }	부등 연산 (≠)
$gt	{ <field>: { $gt: <value> } }	초과 연산 (＞)
$gte	{ <field>: { $gte: <value> } }	이상 연산 (≥)
$lt	{ <field>: { $lt: <value> } }	미만 연산 (＜)
$lte	{ <field>: { $lte: <value> } }	이하 연산 (≤)
$in	{ <field>: { $in: [<value1>, <value2>, ... <valueN> ] } }	포함 연산 (\(\in\))
$nin	{ <field>: { $nin: [ <value1>, <value2> ... <valueN> ] } }	부정 포함 연산 (\(\notin\)

Logical (논리 연산자)

Name	Syntax	Description
$and	{ $and: [ { <expr1> }, { <expr2> } , ... , { <exprN> } ] }	AND 연산
$not	{ <field>: { $not: { <op-expr> } } }	NOT 연산
$nor	{ $nor: [ { <expr1> }, { <expr2> }, ...  { <exprN> } ] }	NOR 연산
$or	{ $or: [ { <expr1> }, { <expr2> }, ... , { <exprN> } ] }	OR 연산

Element (논리 연산자)

Name	Syntax	Description
$exists	{ field: { $exists: } }	Matches documents that have the specified field.
$type	{ field: { $type: <BSON type> } } { field: { $type: [ <BSON type1> , <BSON type2>, ... ] } }	Selects documents if a field is of the specified type.

Evaluation

Name	Description
$expr	Allows use of aggregation expressions within the query language.
$jsonSchema	Validate documents against the given JSON Schema.
$mod	Performs a modulo operation on the value of a field and selects documents with a specified result.
$regex	Selects documents where values match a specified regular expression.
$text	Performs text search.
$where	Matches documents that satisfy a JavaScript expression.

Geospatial

Name	Description
$geoIntersects	Selects geometries that intersect with a GeoJSON geometry. The 2dsphere index supports $geoIntersects.
$geoWithin	Selects geometries within a bounding GeoJSON geometry. The 2dsphere and 2d indexes support $geoWithin.
$near	Returns geospatial objects in proximity to a point. Requires a geospatial index. The 2dsphere and 2d indexes support $near.
$nearSphere	Returns geospatial objects in proximity to a point on a sphere. Requires a geospatial index. The 2dsphere and 2d indexes support $nearSphere.

Array (배열 연산자)

Name	Description
$all	Matches arrays that contain all elements specified in the query.
$elemMatch	Selects documents if element in the array field matches all the specified $elemMatch conditions.
$size	Selects documents if the array field is a specified size.

Bitwise (비트 연산자)

Name	Description
$bitsAllClear	Matches numeric or binary values in which a set of bit positions all have a value of 0.
$bitsAllSet	Matches numeric or binary values in which a set of bit positions all have a value of 1.
$bitsAnyClear	Matches numeric or binary values in which any bit from a set of bit positions has a value of 0.
$bitsAnySet	Matches numeric or binary values in which any bit from a set of bit positions has a value of 1.

---

Projection Operators (프로젝션 연산자)

Name	Description
$	Projects the first element in an array that matches the query condition.
$elemMatch	Projects the first element in an array that matches the specified $elemMatch condition.
$meta	Projects the document's score assigned during $text operation.
$slice	Limits the number of elements projected from an array. Supports skip and limit slices.

---

Miscellaneous Operators (기타 연산자)

Name	Description
$comment	Adds a comment to a query predicate.
$rand	Generates a random float between 0 and 1.

---

Reference: MongoDB Documentation (URL)