Update key value where another key equals some value in MongoDB?

Use $elemMatch fir this with $set

Let us first create a collection with documents −

> dbkeyValueDemoinsertOne(    {       "_id" : new ObjectId(),       "CustomerDetails" : [          {             "Name" : "Chris",             "Age" :24,          },          {             "Name" : "Robert",             "Age" :29,          },          {             "Name" : "David",             "Age" :35,          }       ]    } ); {    "acknowledged" : true,    "insertedId" : ObjectId("5cefcf36ef71edecf6a1f6bf") }

Following is the query to display all documents from a collection with the help of find() method −

> dbkeyValueDemofind()pretty();

Output

{    "_id" : ObjectId("5cefcf36ef71edecf6a1f6bf"),    "CustomerDetails" : [       {          "Name" : "Chris",          "Age" : 24       },       {          "Name" : "Robert",          "Age" : 29       },       {          "Name" : "David",          "Age" : 35       }    ] }

Here is the query to update key value where different key equals some value −

> dbkeyValueDemoupdate(    {"CustomerDetails":{"$elemMatch":{"Name":"David"}}},    {"$set":{"CustomerDetails$Age":56}});    WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 } )

Let us check the document once again −

> dbkeyValueDemofind()pretty();

Output

{    "_id" : ObjectId("5cefcf36ef71edecf6a1f6bf"),    "CustomerDetails" : [       {          "Name" : "Chris",          "Age" : 24       },       {          "Name" : "Robert",          "Age" : 29       },       {          "Name" : "David",          "Age" : 56       }    ] }