How to do filter by keyword in Firebase? - firebase

Question

I have a Firebase database structure like this
{
"5ZhJG1NACDdG9WoNZWrBoYGkIpD3" : {
"Company" : {
"5ZhJG1NACDdG9WoNZWrBoYGkIpD3" : {
"authTime" : 1532061957,
"companyName" : "Scopic Software",
"contactName" : "Hoang Scopic",
"email" : "hoang.trinh#scopicsoftware.com",
"firebaseID" : "5ZhJG1NACDdG9WoNZWrBoYGkIpD3",
"isFirstLogin" : false,
"phoneNumber" : "1234567890",
"schoolName" : "MIT",
"teachers" : {
"aOpjnzHpDiZ7uwQQqJoinGvM9ZD3" : "0"
}
}
}
},
"AhZc9B02goOtZ6qBNhz9W0K6Esg2" : {
"Subscription" : {
"-LHlQ4OhijzzFY5HZOT4" : {
"firebaseID" : "-LHlQ4OhijzzFY5HZOT4",
"period" : {
"endAt" : "1533194625",
"startAt" : "1531985025"
},
"status" : "trial"
}
},
"Teacher" : {
"AhZc9B02goOtZ6qBNhz9W0K6Esg2" : {
"authTime" : 1532061932,
"email" : "hoang.trinhj#gmail.com",
"firebaseID" : "AhZc9B02goOtZ6qBNhz9W0K6Esg2",
"isFirstLogin" : false,
"name" : "Hoang Trinh",
"schoolName" : "HUST",
"subscriptions" : {
"-LHlQ4OhijzzFY5HZOT4" : "0"
}
}
}
},
"aOpjnzHpDiZ7uwQQqJoinGvM9ZD3" : {
"Subscription" : {
"-LHlWnpNZazBC5lpXLi0" : {
"firebaseID" : "-LHlWnpNZazBC5lpXLi0",
"period" : {
"endAt" : "1533196388",
"startAt" : "1531986788"
},
"status" : "trial"
}
},
"Teacher" : {
"aOpjnzHpDiZ7uwQQqJoinGvM9ZD3" : {
"Company" : {
"5ZhJG1NACDdG9WoNZWrBoYGkIpD3" : "0"
},
"authTime" : 1532060884,
"email" : "piavghoang#gmail.com",
"firebaseID" : "aOpjnzHpDiZ7uwQQqJoinGvM9ZD3",
"isFirstLogin" : false,
"subscriptions" : {
"-LHlWnpNZazBC5lpXLi0" : "0"
}
}
}
},
"ooR32SjABdOYEkWX6dzy4fE5Kym1" : {
"Admin" : {
"email" : "admin#test.com",
"firstName" : "Hoang",
"lastName" : "Trinh",
"password" : "123456xx"
},
"isAdmin" : true
}
}
This is data in an existing system, so I can't change its structure.
Now I need to write an API to list these records filtered by "email" attribute there (it's nested inside a key).
How can I do a search for this email?
There is one solution that I thought about. It's just getting the whole json back and process data in code (not using Firebase database query functions).
But I can't do that, because AFTER filtering, I need to do paging also.
In order to make the pagination, I need to use query functions like "sortByChild" or "limitToLast", so I have to use these query functions with filtering.
Thank you.
EDIT:
My current implementation for pagination:
getUsers: async (page, perPage, searchTerm) => {
const db = fbAdmin.db();
let dbRef = await db.ref();
if (searchTerm) {
// TODO: Add filter logic here
}
let totalItems = await dbRef.once('value');
let totalItemsNumber = await Object.keys(totalItems.toJSON()).length;
// Calculate for pagination
let lastItemId;
if ((page - 1) * perPage + 1 > totalItemsNumber) {
lastItemId = null;
} else {
let lastItems = await dbRef.orderByKey().limitToLast((page - 1) * perPage + 1).once('value');
lastItemId = Object.keys(lastItems.toJSON())[0];
}
// Do the pagination
let snap;
let data;
if (lastItemId) {
snap = await dbRef.orderByKey().endAt(lastItemId).limitToLast(perPage).once('value');
data = snap.toJSON();
} else {
data = {};
}
let users = Object.keys(data).map(key => {
if (data[key][KEY]) { // Check if it's an admin
return {
role: TYPE_ADMIN,
email: data[key][KEY].email,
name: data[key][KEY].firstName + " " + data[key][KEY].lastName
}
} else if (data[key][Company.KEY]) { // Check if it's a company member
return {
role: TYPE_COMPANY_MEMBER,
email: data[key][Company.KEY][key].email,
name: data[key][Company.KEY][key].name,
schoolName: data[key][Company.KEY][key].schoolName
}
} else if (data[key][Teacher.KEY]) { // Check if it's a teacher
if (data[key][Teacher.KEY][key][Company.KEY]) { // Check if it's a company teacher
return {
role: TYPE_COMPANY_TEACHER,
email: data[key][Teacher.KEY][key].email,
name: data[key][Teacher.KEY][key].name,
schoolName: data[key][Teacher.KEY][key].schoolName,
subscription: data[key][Subscription.KEY]
}
} else { // Check if it's an individual teacher
return {
role: TYPE_INDIVIDUAL_TEACHER,
email: data[key][Teacher.KEY][key].email,
name: data[key][Teacher.KEY][key].name,
schoolName: data[key][Teacher.KEY][key].schoolName,
subscription: data[key][Subscription.KEY]
}
}
} else {
return null;
}
});
return users || null;
},