How to update particular value of child in Firebase DB

Question

I am following this document. Following is my code for update:

func updateDealResultToServer(key:String,dealResult : String)
{

    let post = ["dealResul": dealResult]
    let childUpdates =
        ["/komal_xyz/\(key)": post
        ]

    rootRef.updateChildValues(childUpdates)

}

This Is my Firebase database structure:

I want to only change the value for dealResult. Whenever I try to run above code for particular child node like 1473670100726, other value except dealResul is deleted.

@omal Kamble:when i remove value from listing from one device that value remove from another device at same time ?so how that happen ? please explain for android. i dont understand how work? — Sachin Suthar, Aug 08 '17 at 11:17

score 7 · Accepted Answer · edited May 23 '17 at 12:34

For Updating values at a particular node in Firebase Realtime Database, use:-

You can either use runTransactionBlock:

  func updateTotalNoOfPost(completionBlock : (() -> Void)){


let prntRef = FIRDatabase.database().reference().child("komal_kyz").child(your_AuroID).child("dealResul")

prntRef.runTransactionBlock({ (resul) -> FIRTransactionResult in
    if let dealResul_Initial = resul.value as? Int{

        //resul.value = dealResul_Initial + 1
        //Or HowSoEver you want to update your dealResul. 
         return FIRTransactionResult.successWithValue(resul)
    }else{

        return FIRTransactionResult.successWithValue(resul)

    }
    }, andCompletionBlock: {(error,completion,snap) in

            print(error?.localizedDescription)
            print(completion)
            print(snap)
        if !completion {

           print("Couldn't Update the node")
        }else{

            completionBlock()
        }
    })

 }

While calling this function:-

updateTotalNoOfPost{
       print("Updated")
      }

Or just call updateValues

    let prntRef  = FIRDatabase.database().reference().child("komal_kyz").child(your_AuroID)
    prntRef.updateChildValues(["dealResul":dealResult])

PS:- Prefer using runTransactionBlock: instead of .updateChildValues if you only want to increment a particular node. Also read this: -https://stackoverflow.com/a/39458044/6297658

score 5 · Answer 2 · answered Sep 13 '16 at 07:40

5

I suggest using setValue for single child updates (keep in mind that I am using Swift 3, slight syntax changes may apply but you should be fine):

rootRef.child("komal_kyz").child(key).setValue(["dealResul":dealResult])

answered Sep 13 '16 at 07:40

tech4242

2,348
2
23
33

Is there a reason why using `setValue` is better? – Josh Mar 28 '18 at 14:34

score 1 · Answer 3 · answered Feb 09 '18 at 09:05

1

let ref = FIRDatabase.database().reference().root.child("users").child("childKey").updateChildValues(["childKeyForUpdate": "NewData"])

answered Feb 09 '18 at 09:05

Er. Deependra Thakur

9
5

Would you please elaborate on that? – mrun Feb 09 '18 at 09:30
Can you provide some details? – aircraft Feb 09 '18 at 11:02
firebase is a database which is used for implement chatting functionality in your application , firebase provide socket programming. if you want to update value of any selected chilled then this code help-full for you in which "user" is a your table name on firebaseDataBase and "childKey" is a chilled of user table and "childKeyForUpdate" is your selected key for update and the "NewData" id your latest data for replace to old – Er. Deependra Thakur May 11 '18 at 09:09

How to update particular value of child in Firebase DB

3 Answers3

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