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Use $sort in MongoDB aggregation. Let us create a collection with documents −> db.demo652.insertOne({ ... value:10, ... "details" : [{ ... "ProductName" : "Product-1", ... "ProductQuantity" : 8, ... "ProductPrice" : 500 ... }, { ... "ProductName" : "Product-2", ... "ProductQuantity" : 7, ... "ProductPrice" : 500 ... ... }] ... } ... ); { "acknowledged" : true, "insertedId" : ObjectId("5e9f0730e3c3cd0dcff36a62") } > > db.demo652.insertOne({ ... value:5, ... ... Read More
To avoid performance issues in MongoDB, use the concept of index. Let us create a collection with documents −> db.demo531.createIndex({"CountryName":"text", "Name":"text"});{ "createdCollectionAutomatically" : true, "numIndexesBefore" : 1, "numIndexesAfter" : 2, "ok" : 1 } > db.demo531.insertOne({CountryName:"US", "Name":"Chris"});{ "acknowledged" : true, "insertedId" : ObjectId("5e8b2b60ef4dcbee04fbbbf2") } > db.demo531.insertOne({CountryName:"UK", "Name":"David"});{ "acknowledged" : true, "insertedId" : ObjectId("5e8b2b6cef4dcbee04fbbbf3") } > db.demo531.insertOne({CountryName:"AUS", "Name":"chris"});{ "acknowledged" : true, "insertedId" : ObjectId("5e8b2b74ef4dcbee04fbbbf4") } > db.demo531.insertOne({CountryName:"US", "Name":"CHRIS"});{ "acknowledged" : true, "insertedId" : ObjectId("5e8b2badef4dcbee04fbbbf5") }Display all documents from a collection with the help of find() method −> db.demo531.find();This will ... Read More
If there are null values also, then implement ORDERBY using sort().Note − Since, starting in MongoDB v3.2, the $orderby operator deprecated in the mongo shell. Use cursor.sort() instead.Let us create a collection with documents −> db.demo530.insertOne({"Name":"Chris"});{ "acknowledged" : true, "insertedId" : ObjectId("5e8b2990ef4dcbee04fbbbec") } > db.demo530.insertOne({"Name":null});{ "acknowledged" : true, "insertedId" : ObjectId("5e8b2991ef4dcbee04fbbbed") } > db.demo530.insertOne({"Name":"David"});{ "acknowledged" : true, "insertedId" : ObjectId("5e8b2992ef4dcbee04fbbbee") } > db.demo530.insertOne({"Name":"Adam"});{ "acknowledged" : true, "insertedId" : ObjectId("5e8b2995ef4dcbee04fbbbef") } > db.demo530.insertOne({"Name":null});{ "acknowledged" : true, "insertedId" : ObjectId("5e8b2999ef4dcbee04fbbbf0") } > db.demo530.insertOne({"Name":"Carol"});{ "acknowledged" : true, "insertedId" : ObjectId("5e8b299eef4dcbee04fbbbf1") }Display ... Read More
To group by _id in MongoDB, use $group. Let us create a collection with documents −> db.demo529.insertOne({"Score":10});{ "acknowledged" : true, "insertedId" : ObjectId("5e8b1d5bef4dcbee04fbbbe4") } > db.demo529.insertOne({"Score":20});{ "acknowledged" : true, "insertedId" : ObjectId("5e8b1d5fef4dcbee04fbbbe5") } > db.demo529.insertOne({"Score":10});{ "acknowledged" : true, "insertedId" : ObjectId("5e8b1d61ef4dcbee04fbbbe6") } > db.demo529.insertOne({"Score":10});{ "acknowledged" : true, "insertedId" : ObjectId("5e8b1d62ef4dcbee04fbbbe7") }Display all documents from a collection with the help of find() method −> db.demo529.find();This will produce the following output −{ "_id" : ObjectId("5e8b1d5bef4dcbee04fbbbe4"), "Score" : 10 } { "_id" : ObjectId("5e8b1d5fef4dcbee04fbbbe5"), "Score" : 20 } { "_id" : ObjectId("5e8b1d61ef4dcbee04fbbbe6"), "Score" : 10 ... Read More
To match collection items by id, use $in in MongoDB. Let us create a collection with documents −> db.demo528.insertOne({"Name":"Chris", Age:21});{ "acknowledged" : true, "insertedId" : ObjectId("5e8b00d2ef4dcbee04fbbbe0") } > db.demo528.insertOne({"Name":"Bob", Age:22});{ "acknowledged" : true, "insertedId" : ObjectId("5e8b00d9ef4dcbee04fbbbe1") } > db.demo528.insertOne({"Name":"David", Age:20});{ "acknowledged" : true, "insertedId" : ObjectId("5e8b00e0ef4dcbee04fbbbe2") }Display all documents from a collection with the help of find() method −> db.demo528.find();This will produce the following output −{ "_id" : ObjectId("5e8b00d2ef4dcbee04fbbbe0"), "Name" : "Chris", "Age" : 21 } { "_id" : ObjectId("5e8b00d9ef4dcbee04fbbbe1"), "Name" : "Bob", "Age" : 22 } { "_id" : ObjectId("5e8b00e0ef4dcbee04fbbbe2"), "Name" : "David", ... Read More
For this, use $group and within that, we need to work with $sum to add. Let us create a collection with documents −> db.demo527.insertOne({"Price":45.5});{ "acknowledged" : true, "insertedId" : ObjectId("5e8aff2fef4dcbee04fbbbdc") } > db.demo527.insertOne({"Price":55.5});{ "acknowledged" : true, "insertedId" : ObjectId("5e8aff34ef4dcbee04fbbbdd") } > db.demo527.insertOne({"Price":100.4});{ "acknowledged" : true, "insertedId" : ObjectId("5e8aff39ef4dcbee04fbbbde") } > db.demo527.insertOne({"Price":200.6});{ "acknowledged" : true, "insertedId" : ObjectId("5e8aff40ef4dcbee04fbbbdf") }Display all documents from a collection with the help of find() method −> db.demo527.find();This will produce the following output −{ "_id" : ObjectId("5e8aff2fef4dcbee04fbbbdc"), "Price" : 45.5 } { "_id" : ObjectId("5e8aff34ef4dcbee04fbbbdd"), "Price" : 55.5 } ... Read More
To update an array with $push, use updateOne() in MongoDB. Let us create a collection with documents −> db.demo526.insertOne( ... { ... ... "CountryName": "US", ... "TeacherName": "Bob", ... "StudentInformation": [ ... { ... "Name": "Chris", ... "Subject": "MySQL", ... "ListOfMailId":[] ... }, ... { ... "Name": "David", ... "Subject": "MongoDB", ... "ListOfMailId":[] ... ... } ... ] ... } ... Read More
For this, use $and along with $regex. The $and performs a logical AND operation on an array of one or more expressions and selects the documents that satisfy all the expressions in the array.Let us create a collection with documents −> db.demo525.insertOne({"details":[{Name:"Chris", "CountryName":"US"}]});{ "acknowledged" : true, "insertedId" : ObjectId("5e8ae5ef437efc8605595b66") } > db.demo525.insertOne({"details":[{Name:"Bob", "CountryName":"UK"}]});{ "acknowledged" : true, "insertedId" : ObjectId("5e8ae5f8437efc8605595b67") } > db.demo525.insertOne({"details":[{Name:"chris", "CountryName":"us"}]});{ "acknowledged" : true, "insertedId" : ObjectId("5e8ae602437efc8605595b68") } > db.demo525.insertOne({"details":[{Name:"Mike", "CountryName":"UK"}]});{ "acknowledged" : true, "insertedId" : ObjectId("5e8ae60b437efc8605595b69") }Display all documents from a collection with the help of find() method −> ... Read More
To search date between two dates in MongoDB, use $gte and $lt. Let us create a collection with documents −> db.demo524.insertOne({"EndDate":new ISODate("2020-01-19")});{ "acknowledged" : true, "insertedId" : ObjectId("5e8adbe5437efc8605595b63") } > db.demo524.insertOne({"EndDate":new ISODate("2020-01-20")});{ "acknowledged" : true, "insertedId" : ObjectId("5e8adbec437efc8605595b64") } > db.demo524.insertOne({"EndDate":new ISODate("2020-12-31")});{ "acknowledged" : true, "insertedId" : ObjectId("5e8adbf3437efc8605595b65") }Display all documents from a collection with the help of find() method −> db.demo524.find();This will produce the following output −{ "_id" : ObjectId("5e8adbe5437efc8605595b63"), "EndDate" : ISODate("2020-01-19T00:00:00Z") } { "_id" : ObjectId("5e8adbec437efc8605595b64"), "EndDate" : ISODate("2020-01-20T00:00:00Z") } { "_id" : ObjectId("5e8adbf3437efc8605595b65"), "EndDate" : ISODate("2020-12-31T00:00:00Z") }Following is the query ... Read More
For float conversion, use parseFloat() in MongoDB. Let us create a collection with documents −> db.demo523.insertOne({"details":{values:"-0.45"}});{ "acknowledged" : true, "insertedId" : ObjectId("5e89b7efb3fbf26334ef611f") }Display all documents from a collection with the help of find() method −> db.demo523.find();This will produce the following output −{ "_id" : ObjectId("5e89b7efb3fbf26334ef611f"), "details" : { "values" : "-0.45" } }Following is the query that does not result 0 in the conversion of float −>db.getCollection('demo523').find({}).forEach( function(d) ... { d.details.values = parseFloat( d.details.values ) ... db.getCollection('demo523').save(d)} );Display all documents from a collection with the help of find() method −> db.demo523.find();This will produce the following output −{ "_id" ... Read More