How to query objects from a set of key IDs in Firebase? - flutter

Question

Consider the following data structure:
{
"company": {
"idCompany1": {
"data": {
"address": "",
"companyName": "Company 1",
"logo": "assets/Logo1.png",
"nit": "",
"phone": ""
}
},
"idCompany2": {
"data": {
"address": "",
"companyName": "Company 2",
"logo": "assets/Logo2.png",
"nit": "",
"phone": ""
}
},
"idCompany3": {
"data": {
"address": "",
"companyName": "Company 3",
"logo": "assets/Logo3.png",
"nit": "",
"phone": ""
}
}
},
"users": {
"idUser1": {
"data": "user1#test.com",
"companies": {
"idCompany1": true,
"idCompany3": true
}
},
"idUser2": {
"data": "user2#test.com",
"companies": {
"idCompany2": true
}
}
}
}
Basically what I need to do in the case of user1 is to read the data of the companies to which it belongs, this is Company 1 and Company 3. How can I do that?
The way I found, is by obtaining a list of IDs of those companies, which I have in listaIdEmpresas and then consulting each one through a forEach loop in the following way:
Future<List<EmpresaDatosModel>> cargarEmpresaDatosListado(List<String> listaIdEmpresas) async {
final List<EmpresaDatosModel> listaEmpresas = new List();
listaIdEmpresas.forEach((id) async {
Query resp = db.child('company/$id/data');
final snapshot = await resp.once();
final temp = EmpresaDatosModel.fromJson(Map<String,dynamic>.from(snapshot.value));
temp.idEmpresa = id;
listaEmpresas.add(temp);
print('${temp.companyName} up');
await resp.once().then((snapshot) {});
});
listaEmpresas.forEach((element) {print('Emp ${element.companyName}');});
return listaEmpresas;
}
However, this process is not efficient and I need to manage a delay for waiting the loop.
What would be the right way to do query data from a list of Ids directly?