javascript - Get an unknown key name from Firebase function database trigger -

i'm new firebase functions , trying understand how key database .oncreate trigger. here example:

exports.createuserrounddata =  functions.database.ref('/data/players/{user_key}/').oncreate(event => {      var eventdata = event.data.val();      var userkey = event.params.user_key;      var itemkey = eventdata.items; // returns object  }); 

the structure is:

players > user_key > items > item_key > data 

in above scenario how can retrieve item_key?

yes can,

you need :

exports.createuserrounddata = functions.database.ref('/data/players/{user_key}/').oncreate(event => {     var userkey = event.params.user_key; // user key parameter     var eventsnapshot = event.data; // player data     var itemssnapshot = eventsnapshot.child('items'); // items data      itemssnapshot.foreach(function(itemsnapshot) { // each item         var itemkey = itemsnapshot.key; // item key         var itemdata = itemsnapshot.val(); // item data     }); }); 

here firebase cloud functions documentation.