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How to find and modify a value in a nested array?
To find and modify a value in a nested array, you can use update command. Let us first create a collection with documents
> db.findAndModifyAValueInNestedArrayDemo.insertOne( { "CompanyName" :
"Amazon", "DeveloperDetails" : [ { "ProjectName" : "Online Book
Store", "TeamSize" : "5" }, { "ProjectName" : "Library
Management System", "TeamSize" : "7" }, { "ProjectName" :
"Online Banking Application", "TeamSize" : "15" } ] } );
{
"acknowledged" : true,
"insertedId" : ObjectId("5ca275226304881c5ce84b9f")
}Following is the query to display all documents from a collection with the help of find() method
> db.findAndModifyAValueInNestedArrayDemo.find().pretty();
This will produce the following output
{
"_id" : ObjectId("5ca275226304881c5ce84b9f"),
"CompanyName" : "Amazon",
"DeveloperDetails" : [
{
"ProjectName" : "Online Book Store",
"TeamSize" : "5"
},
{
"ProjectName" : "Library Management System",
"TeamSize" : "7"
},
{
"ProjectName" : "Online Banking Application",
"TeamSize" : "15"
}
]
}Following is the query to find and modify a value in a nested array. We are modifying the TeamSize to 20 for ProjectName: "Online Banking Application"
> db.findAndModifyAValueInNestedArrayDemo.update( { DeveloperDetails: { $elemMatch: {
ProjectName: "Online Banking Application" } } }, { $set: { 'DeveloperDetails.$.TeamSize':
'20' } } );
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })Let us check the document is modified with value 20 or not
> db.findAndModifyAValueInNestedArrayDemo.find().pretty();
This will produce the following output
{
"_id" : ObjectId("5ca275226304881c5ce84b9f"),
"CompanyName" : "Amazon",
"DeveloperDetails" : [
{
"ProjectName" : "Online Book Store",
"TeamSize" : "5"
},
{
"ProjectName" : "Library Management System",
"TeamSize" : "7"
},
{
"ProjectName" : "Online Banking Application",
"TeamSize" : "20"
}
]
}
Updated on: 30-Jul-2019
154 Views
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