MongoDB query to match each element in a documents array to a condition?

You can use every() in MongoDB for this. Let us create a collection with documents −

> db.arrayConditionDemo.insertOne({"Name":"John","Marks":[40,43,45]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cbdbd06de8cc557214c0e1a") } > db.arrayConditionDemo.insertOne({"Name":"Mike","Marks":[45]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cbdbd17de8cc557214c0e1b") } > db.arrayConditionDemo.insertOne({"Name":"Chris","Marks":[43,45,59,69,78,89]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cbdbd3cde8cc557214c0e1c") }

Display all documents from a collection with the help of find() method. The query is as follows −

> db.arrayConditionDemo.find().pretty();

This will produce the following output −

{    "_id" : ObjectId("5cbdbd06de8cc557214c0e1a"),    "Name" : "John",    "Marks" : [       40,       43,       45    ] } {    "_id" : ObjectId("5cbdbd17de8cc557214c0e1b"),    "Name" : "Mike",    "Marks" : [       45    ] } {    "_id" : ObjectId("5cbdbd3cde8cc557214c0e1c"),    "Name" : "Chris",    "Marks" : [       43,       45,       59,       69,       78,       89    ] }

Following is the query to match each element in a documents array to a condition −

> db.arrayConditionDemo.find("return this.Marks.every(function(m) { return (m >= 40 && m<= 100) })");

This will produce the following output −

{ "_id" : ObjectId("5cbdbd06de8cc557214c0e1a"), "Name" : "John", "Marks" : [ 40, 43, 45 ] } { "_id" : ObjectId("5cbdbd17de8cc557214c0e1b"), "Name" : "Mike", "Marks" : [ 45 ] } { "_id" : ObjectId("5cbdbd3cde8cc557214c0e1c"), "Name" : "Chris", "Marks" : [ 43, 45, 59, 69, 78, 89 ] }