Below is a MongoDB query cheat sheet covering common operations and syntax for interacting with MongoDB databases:
Basic Queries
Select All Documents:
db.collection.find()
Select Specific Fields:
db.collection.find({}, { field1: 1, field2: 1 })
Query with Equality:
db.collection.find({ field: "value" })
Query with AND Operator:
db.collection.find({ field1: "value1", field2: "value2" })
Query with OR Operator:
db.collection.find({ $or: [{ field1: "value1" }, { field2: "value2" }] })
Comparison Operators
Greater Than:
db.collection.find({ field: { $gt: value } })
Less Than:
db.collection.find({ field: { $lt: value } })
Greater Than or Equal To:
db.collection.find({ field: { $gte: value } })
Less Than or Equal To:
db.collection.find({ field: { $lte: value } })
Element Operators
Existence Check:
db.collection.find({ field: { $exists: true } })
Array Element Match:
db.collection.find({ arrayField: { $elemMatch: { $gt: 10 } } })
Logical Operators
Logical AND:
db.collection.find({ $and: [{ field1: "value1" }, { field2: "value2" }] })
Logical OR:
db.collection.find({ $or: [{ field1: "value1" }, { field2: "value2" }] })
Logical NOT:
db.collection.find({ field: { $not: { $eq: value } } })
Update Operations
Update Documents Matching a Condition:
db.collection.update({ field: "value" }, { $set: { newField: "newValue" } })
Update Multiple Documents:
db.collection.updateMany({ field: "value" }, { $set: { newField: "newValue" } })
Delete Operations
Delete Documents Matching a Condition:
db.collection.deleteOne({ field: "value" })
Delete Multiple Documents:
db.collection.deleteMany({ field: "value" })
Indexing
Create Index:
db.collection.createIndex({ field: 1 })
List Indexes:
db.collection.getIndexes()
Aggregation
Aggregation Pipeline:
db.collection.aggregate([
{ $match: { field: "value" } },
{ $group: { _id: "$field", count: { $sum: 1 } } }
])
This cheat sheet provides a quick reference for common MongoDB queries. Always refer to the official MongoDB documentation for more detailed information and additional query operators.