Query nested array by more than one condition in MongoDB

To query nested array, use $elemMatch in MongoDB. Let us create a collection with documents −

> db.demo203.insertOne({
...   "_id" : "101",
...   "Name" : "Chris",
...   "details1" : [
...      {
...         "empName" : "David",
...         "salary" : "50000",
...         "technology" : [
...            "MySQL",
...            "MongoDB"
...         ]
...      },
...      {
...         "empName" : "Carol",
...         "salary" : "70000",
...
...         "technology" : [
...            "Java",
...            "Spring"
...         ]
...      }
...   ]
...}
...);
{ "acknowledged" : true, "insertedId" : "101" }

Display all documents from a collection with the help of find() method −

> db.demo203.find();

This will produce the following output −

{
   "_id" : "101", "Name" : "Chris", "details1" : [
      { "empName" : "David", "salary" : "50000", "technology" : [ "MySQL", "MongoDB" ] },
      { "empName" : "Carol", "salary" : "70000", "technology" : [ "Java", "Spring" ] } ]
}

Here is how to query nested array by more than one condition −

> db.demo203.find(
...      {details1: { $elemMatch:{"technology" : "MySQL", "empName":"David"}}}
...   ).pretty()

This will produce the following output −

{
   "_id" : "101",
   "Name" : "Chris",
   "details1" : [
      {
         "empName" : "David",
         "salary" : "50000",
         "technology" : [
            "MySQL",
            "MongoDB"
         ]
      },
      {
         "empName" : "Carol",
         "salary" : "70000",
         "technology" : [
            "Java",
            "Spring"
         ]
      }
   ]
}

AmitDiwan

Published on 27-Mar-2020 15:02:07