How to get the key from the value in firebase

Question

How do I get the key \"-KLpcURDV68BcbAvlPFy\" when I know the field \"name\" contains \"efg\" in the following structure in Firebase.

clubs
    -KLpcURDV68Bc         


        

Answer 1

We can use HashMap.

initialize:

String for storing Key value. ModelClass for storing you data.

val hashMap: HashMap = hashMapOf()
databaseReference.child("/Product").orderByChild("ProductName")
        .addValueEventListener(object : ValueEventListener {
            override fun onCancelled(p0: DatabaseError) {

            }

            override fun onDataChange(p0: DataSnapshot) {
                /*p0.children.mapNotNullTo(models) { it.getValue(ProductModel::class.java) }.run {

                }*/
                p0.children.forEach {
                    val value = it.getValue(ProductModel::class.java) as ProductModel
                    hashMap[it.key!!] = value
                }.run { adp.update(hashMap) }
            }
        })

after this we can also get key & its value by using (index)

5 is Index

hashMap.keys.elementAt(5)
hashMap.values.elementAt(5)