MongoDB: update the string value for all docs where it is existed

Question

collectionABC
/* 1 */
{
    "DealerId" : "39823398",
    "VehicleCategory" : [ 
        {
            "seqId" : "23987134983471982134HAD",
            "vehicleName" : "BMW",
            "vehicleImage" : "images/vehicle/270029.gif"
        }, 
        {
            "seqId" : "293874KJHKHKJH7878",
            "vehicleName" : "Audi",
            "vehicleImage" : "images/vehicle/27022398.gif"
        }
    ]
}

/* 2 */
{
    "DealerId" : "3987398",
    "VehicleCategory" : [ 
        {
            "seqId" : "2234423987134983471982134HAD",
            "vehicleName" : "Honda",
            "vehicleImage" : "images/vehicle/270029.gif"
        }, 
        {
            "seqId" : "9834293874KJHKHKJH7878",
            "vehicleName" : "Toyota",
            "vehicleImage" : "images/vehicle/27022398.gif"
        }
    ]
}

I have 100k docs with the above pattern and needs to be update from ".gif" to ".png" for all existing the docs. The rest of everything should be remain same.

After update the documents the result should be looks like:

collectionABC
/* 1 */
{
    "DealerId" : "39823398",
    "VehicleCategory" : [ 
        {
            "seqId" : "23987134983471982134HAD",
            "vehicleName" : "BMW",
            "vehicleImage" : "images/vehicle/270029.png"
        }, 
        {
            "seqId" : "293874KJHKHKJH7878",
            "vehicleName" : "Audi",
            "vehicleImage" : "images/vehicle/27022398.png"
        }
    ]
}

/* 2 */
{
    "DealerId" : "3987398",
    "VehicleCategory" : [ 
        {
            "seqId" : "2234423987134983471982134HAD",
            "vehicleName" : "Honda",
            "vehicleImage" : "images/vehicle/270029.png"
        }, 
        {
            "seqId" : "9834293874KJHKHKJH7878",
            "vehicleName" : "Toyota",
            "vehicleImage" : "images/vehicle/27022398.png"
        }
    ]
}

Any thoughts how we can do it in Mongo? Very much appreciated.

Possible duplicate of [How to replace substring in mongodb document](https://stackoverflow.com/questions/12589792/how-to-replace-substring-in-mongodb-document) — dnickless, Aug 27 '18 at 20:32
You can not do it in one query, You will have to read the documents, update at the server end and then update them. — daemon24, Aug 28 '18 at 08:09

score 0 · Answer 1 · answered Aug 28 '18 at 14:42

bulk_update = db.media.initializeUnorderedBulkOp()
db.media.find().forEach(function(e, i) {
   e.VehicleCategory.forEach(function(vehicle, index){
          vehicle.vehicleImage = vehicle.vehicleImage.replace('.gif','.png')
    })
   bulk_update.find({"DealerId": e.DealerId}).update({"$set": e})
})
bulk_update.execute()

If 100k records are there, I would suggest doing the update with a loop selecting 10k at a time, based on your MongoDB capacity.

I am a python guy, sorry if have not used proper JS.

Thanks @Daemon24. By the way, it was throwing the error as : TypeError: vehicle.vehicleImage.replace is not a function — Bhanu Makineni, Aug 28 '18 at 16:02

MongoDB: update the string value for all docs where it is existed

1 Answers1