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To match all the values in MongoDB using aggregation, use $match with $and operator to combine multiple conditions. This allows you to filter documents that satisfy all specified criteria simultaneously. Syntax db.collection.aggregate([ { $match: { $and: [ { "field1": "value1" }, ... Read More
To query an array of embedded documents in MongoDB and push another document, use the $push operator along with update(). You can combine array querying with conditional operations to add new documents only when certain conditions are met. Syntax db.collection.update( { _id: documentId, "arrayField.subField": { $nin: ["value"] } }, { $push: { ... Read More
To find values above a specific value in MongoDB, use the $gte (greater than or equal to) operator to match documents where a field's value meets or exceeds the specified threshold. Syntax db.collectionName.find({ fieldName: { $gte: value } }); Create Sample Data Let us create a collection with price documents ? db.demo571.insertMany([ { "Price": 140 }, { "Price": 100 }, { "Price": 110 }, { "Price": 240 } ]); ... Read More
To count distinct values across all documents in MongoDB, use the aggregate() method with $unwind, $addToSet, and $size operators. This approach flattens arrays, groups unique values, and counts them. Syntax db.collection.aggregate([ { $unwind: "$arrayField" }, { $group: { _id: null, uniqueValues: { $addToSet: "$arrayField" } } }, { $project: { _id: 0, count: { $size: "$uniqueValues" } } } ]); Sample Data db.demo718.insertMany([ { "id": 101, ... Read More
To group dates in nested documents and display their count in MongoDB, use the aggregation pipeline with $unwind to flatten the array, then $group to count occurrences of each date. Syntax db.collection.aggregate([ { $unwind: "$arrayField" }, { $group: { _id: "$arrayField.dateField", count: { $sum: 1 } } ... Read More
To create hierarchical JSON in MongoDB, structure your documents using nested objects and arrays. MongoDB natively supports complex JSON structures with multiple levels of nesting, allowing you to model relationships within a single document. Syntax db.collection.insertOne({ "field1": "value1", "field2": "value2", "nestedObject": { "subField1": "value", "subField2": "value", "nestedArray": [ { ... Read More
To remove an object in a child collection in MongoDB, use the $pull operator combined with the $ positional operator to target the specific nested array and remove matching elements. Syntax db.collection.update( {"parentArray.field": "matchValue"}, { $pull: { "parentArray.$.childArray": {field: "valueToRemove"} } } ); Sample Data db.demo715.insertOne({ _id: 1, details: [ { 'id': '101', ... Read More
MongoDB compound conditions allow you to fetch documents by combining multiple criteria using logical operators. This enables complex filtering with AND, OR, and other conditional operators. Syntax // AND condition (implicit) db.collection.find({field1: "value1", field2: "value2"}) // OR condition db.collection.find({$or: [{field1: "value1"}, {field2: "value2"}]}) // IN operator for multiple values db.collection.find({field: {$in: ["value1", "value2"]}}) Sample Data db.demo714.insertMany([ {FirstName: "Chris", LastName: "Brown"}, {FirstName: "Adam", LastName: "Smith"}, {FirstName: "David", LastName: "Miller"}, {FirstName: "John", LastName: "Doe"} ]); ... Read More
To update tag records in MongoDB quickly, use the $ positional operator along with the update command. The $ operator identifies the first array element that matches the query condition and updates it efficiently. Syntax db.collection.update( { "arrayField.field": "matchValue" }, { $set: { "arrayField.$.field": "newValue" } } ); Create Sample Data Let us create a collection with tag documents ? db.demo713.insertOne({ tags: [ { ... Read More
The $natural operator returns documents in natural insertion order. To reverse the items and get them in reverse insertion order, use $natural:-1 with the sort() method. Syntax db.collection.find().sort({$natural: -1}); Sample Data Let us create a collection with documents ? db.demo710.insertMany([ {id: 101, Name: "Robert"}, {id: 102, Name: "Carol"}, {id: 103, Name: "Mike"}, {id: 104, Name: "Sam"} ]); { "acknowledged": true, "insertedIds": [ ... Read More