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var query = firebase.firestore().collection("book")
query = query.where( )
query = query.where( )
query = query.where( )
query = query.orderBy( )
query.get().then( )
// Now you can put in conditionals to figure out which filters you want to apply at each stage. Just reassign query with each newly added filter.
if (some_condition) {
query = query.where( )
}