let date = '2017-12-20' //date to be set in doc
db.collection("transactions").doc(date).set({
//set an empty object for each doc in transaction before your method
//of setting data
//This will create a field for each doc in transaction
})
.then(()=>{
//your method of setting data here.
})
//Your query method here.
//Now you will be able to query the docs in collection - transaction.
db.collection("transactions").doc("2018-01-02").collection("education-1").get()
.then(function(querySnapshot) {
querySnapshot.forEach(function(doc) {
// doc.data() is never undefined for query doc snapshots
console.log(doc.id, " => ", doc.data());
});
})
.catch(function(error) {
console.log("Error getting documents: ", error);
});