Firebase query equalTo() or startAt().endAt() stop working - firebase

Question

I already tried suggestions from other posts but no success.
I just run into an issue,I got the following code which displays data from Firebase database when user clicks on a specific date.If I comment out (startAt(),endAt()), the recycler gets populated with all data, when I add equalTo() or startAt().endAt()) recycler does not get populated.
The code before was working normally, just recently stopped working and I have no clue why.
The code looks like this:
Bellow is the adapter:
fun calendarAdapt(options:FirebaseRecyclerOptions<ModelCalendar>,dataref:
DatabaseReference,context: Context):FirebaseRecyclerAdapter<ModelCalendar,CalendHold>{
return object :FirebaseRecyclerAdapter<ModelCalendar,CalendHold>(options){
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): CalendHold {
return
CalendHold(LayoutInflater.from(parent.context).inflate(R.layout.list_row_calendar,parent,false))
}
override fun onBindViewHolder(holder: CalendHold, positionc: Int, modelc: ModelCalendar)
{
val postkeyC= getRef(positionc).key
dataref.child(postkeyC!!).addValueEventListener(object:ValueEventListener{
override fun onDataChange(dataSnapshot: DataSnapshot) {
holder.bindlogC(modelc)
}
override fun onCancelled(p0: DatabaseError) {
}
})
}
}
}
This is the Query:
fun query2(cont: LifecycleOwner,selected_date:String):FirebaseRecyclerOptions<ModelCalendar>{
val queryy = FirebaseDatabase.getInstance()
.reference
.child("Ev")
.startAt(selected_date)
.endAt(selected_date)
return FirebaseRecyclerOptions.Builder<ModelCalendar>()
.setQuery(queryy,ModelCalendar::class.java)
.setLifecycleOwner(cont)
.build()
}
Here I apply the adaptor:
mDb = FirebaseDatabase.getInstance().reference.child("Ev")
val c = Calendar.getInstance()
val year2 = c.get(Calendar.YEAR)
val month2 = c.get(Calendar.MONTH)
val day2 = c.get(Calendar.DAY_OF_MONTH)
val dayd= checkDigit(day2)
val monthd= checkDigit(month2+1)
val datetoday = java.lang.StringBuilder()
.append(dayd)
.append("-")
.append(monthd)
.append("-")
.append(year2)
calendinf(datetoday.toString())
calendarid.setOnDateChangeListener { view, year, month, dayOfMonth ->
val month = checkDigit(month+1)
val day = checkDigit(dayOfMonth)
val datesel =StringBuilder()
.append(day)
.append("-")
.append(month)
.append("-")
.append(year)
calendinf(datesel.toString())
}
}
private fun calendinf(selected_date:String){
val options = Queryess().query2(this,selected_date)
val adaptorC = Adaptall().calendarAdapt(options, mDb,this)
calerec!!.adapter=adaptorC!!
}

Answer 1

I fix-it,It was the query, was missing "orderBychild()" field, most probable I mistakenly deleted otherwise cannot explain-it :))