如何将孩子的孩子与本地存储中的数据匹配（Firebase 实时数据库）

Question

My Database structure is like this

I have made a qr code scanner which scan the qr then it match the data from Firebase realtime database in the data matches it go on next page and store that qr code value in local storage. But When I try to mach the data on next page like this:

 var db= app.database() let machine_id = localStorage.getItem('machineid') //output = 8c96aa286f24(Accurate data on console) db.ref('/All_machines/Generator/').orderByKey().equalTo(machine_id).once("value", snapshot => { if (snapshot.exists()){ const userData = snapshot.val(); var snapshot= snapshot.child(machine_id).val(); console.log(userData); //Output: here i didn't get anything not even any error message on console } })

But When i Write the same code after changing database just take out the machine id from generator and write under All_Machines like this

and Change my code according to this then my code start working. but when my machine id is under generator its not working. code:

 var db= app.database() let machine_id = localStorage.getItem('machineid') db.ref('/All_machines').orderByKey().equalTo(machine_id).once("value", snapshot => { if (snapshot.exists()){ const userData = snapshot.val(); var snapshot= snapshot.child(machine_id).val(); console.log(userData); } })

By Running this code i get all the data from Firebase Realtime database

//Output:-

Answer 1

While calling the data from local storage let machine_id = localStorage.getItem('machineid') my data comes with a extra space like this ' 8c96aa286f24' this is the reason why my code was not working i updated the code like this.

 var machine_id_2 = localStorage.getItem('machineid') var space = machine_id_2.split(" ") var machine_id_1 = space[1] db.ref('/All_machines/Generator/').orderByKey().equalTo(machine_id_1).once("value", snapshot => { if (snapshot.exists()){ const userData = snapshot.val(); var snapshot= snapshot.child(machine_id).val(); console.log(userData); } })