How to find if a child with particular value in its fields exist ,in firebase? : I need to find if a child with particular value in one of its fields exists in firebase??
Below given is my db structure.


[I need to check if a child with particular 'chat_id' exists .How to do that ?
[please click here for the db structure]][1]


  [1]: https://i.stack.imgur.com/Qzo0W.png