querying on firebase database android : i'm a beginner in firebase and android i want to make a firebase database i have no problem in that but my problem that i want to take a string from edittext and querying about it in the firebase database . i couldn't understand guide of firebase very well but i noticed that they use Child EventListener() to make query should i use any event ?  i just want to get a value by querying a string
thanks 
that's my database 
[i want to search for a specific text then when it found i send url value to user ][1]


  [1]: http://res.cloudinary.com/dbntfbnzp/image/upload/v1485812719/test.png