CODEWITHSUNDEEP
mongodb
Logesh
Logesh

Reputation: 92

Mongo update query

Hi i need a help for mongo db update query:

For this Data:

{
"services" : [ 
        {
             "type" : "Financial Transaction",
        }],
 "outStandingAmount" : 0
}

This Query is working fine.

db.getCollection('user_informations').updateMany({"outStandingAmount":},{$set: {"outStandingAmount":5000}})

But when i try to update this I got error.

db.getCollection('user_informations').updateMany({"services.type":"Financial Transaction"},{$set: {"services.type":"Financial Trans"}})

Upvotes: 1

Views: 176

Answers (2)

Clement Amarnath
Clement Amarnath

Reputation: 5466

db.collection.find().pretty()

{"_id" : ObjectId("5836b428d7e99005c2585b08"), "services" : [{"type" : "Financial Transaction"}],"outStandingAmount" : 0}
{"_id" : ObjectId("5836c5a9d7e99005c2585b09"), "services" : [{"type" : "Financial Transaction"}], "outStandingAmount" : 2000}

The below query will do the update on matching records.

db.collection.updateMany({"services.type":"Financial Transaction"}, {$set:{
"services":[{"type":"Financial Trans"}]}});

Since we had two matching records in our collection the result of the above updateMany query is 

{ "acknowledged" : true, "matchedCount" : 2, "modifiedCount" : 2 }

Whereas if we use

db.getCollection('user_informations').updateMany({"services.type":"Financial Transaction"},{$set: {"services.type":"Financial Trans"}})

we will get an error msg

    "errmsg" : "cannot use the part (services of services.type) to traverse the element ({services: [ { type: \"Financial Transaction\" } ]})"

When an array is involved then '.' is used to traverse into array elements, even we can traverse into nested arrays using '.', but for modifying an array we have a set of operators, please see https://docs.mongodb.com/v3.2/reference/operator/update-array/

also '.' is used on a update query when we use positional operator $.

Upvotes: 2

satish chennupati
satish chennupati

Reputation: 2650

> You need to make use of the $ operator when you find documents.

db.collection.updateMany(
   {"services.$.type":"Financial Transaction"},
   {$set: {"services.type":"Financial Trans"}}
 )

update your code and replace services.type to services.$.type in the filter section.

ignore my previous query

this will do it

db.collection.find().forEach( function(doc) {
    db.collection.update({"services.type":"Financial Transaction"},
                         {$set:{"services.$.type":"Financial Trans"}});
})

Upvotes: 0

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