如果不知道其密钥，如何在Firebase中更新节点？

Question

In my Firebase DB, I have a list of nodes with auto-generated keys.

"visitors" : {
"-KTmRYgWJkT2nq4i1S1D" : {
  "firstname" : "Jsdfa",
  "lastname" : "Jsdfa",
  "visitorId" : "123"
},
"-KTnUbLCtvdeA6G4p5Xh" : {
  "firstname" : "Jsdfadf",
  "lastname" : "Jfasdgf",
  "visitorId" : "124"
},
"-KToFT1rWLuw6ZbS_xGU" : {
  "firstname" : "Jdfadfa",
  "lastname" : "Jsdfad",
  "visitorId" : "125"
}
}

Firstly, I found a node that needs to be updated, to do this I used following code:

[[_ref child:@"visitors"] queryOrderedByChild:@"visitorId"] queryEqualToValue:@(visitorId)]

And then I need to update it or just delete it. Firebase documentation says that to do this, I need to have a node key.

And that is the problem. I have tried to find a way how to fetch this key, but without any success, I can't find any information about it. Can anyone help me to solve this issue? Any help would be highly appreciated.

Answer 1

The 'visitorId' that you have is the required Node Key.

To delete this node, use:

[[[_ref child:@"visitors"] child:@(visitorId)] removeValue];

To update this node, use:

 [[[_ref child:@"visitors"] child:@(visitorId)] updateChildValues:(dictionary)];

Here, dictionary is a nonnull NSDictionary type, you can pass your values to update in this object as a key-value pair.