How to filter through model? - mongodb

Question

Assuming the standard example of physicians and patiens used by StrongLoop (https://docs.strongloop.com/display/public/LB/HasManyThrough+relations):
common/models/physician.json
{
"name": "Physician",
"base": "PersistedModel",
"properties": {
"name": {
"type": "string"
}
},
"validations": [],
"relations": {
"patients": {
"type": "hasMany",
"model": "Patient",
"foreignKey": "patientId",
"through": "Appointment"
},
common/models/patient.json
{
"name": "Patient",
"base": "PersistedModel",
"properties": {
"name": {
"type": "string"
}
},
"validations": [],
"relations": {
"physicans": {
"type": "hasMany",
"model": "Physician",
"foreignKey": "physicianId",
"through": "Appointment"
},
common/models/appointment.json
{
"name": "Appointment",
"base": "PersistedModel",
"properties": {
"appointmentDate": {
"type": "date"
}
},
"validations": [],
"relations": {
"physician": {
"type": "belongsTo",
"model": "Physician",
"foreignKey": "physicianId"
},
"patient": {
"type": "belongsTo",
"model": "Patient",
"foreignKey": "patientId"
},
how can I get patient from physician filtering by appointmentDate?
I tried to use something like this:
Physician.findOne({
"where": {"id": physId},
"include": {
"relation": "patients",
"scope": {
"where": {
"appointmentDate": { "gt": fixedDate }
}
}
}
}, callback);
but it seems that Loopback look for appointmentDate on Patient model instead of on Appointment model.
Some useful hint?
Thanks!

Answer 1

I think you may have something wrong in your mongo query understanding.
The operators in mongo must in the beginning of '$', so your gt should change to $gt, where should change to $where
To get patient from physician filtering by appointmentDate, we can do it by 2 steps, suppose you have the id(physId) of a specific physician.
var appointments = Appointment.find({
"relation.physician.foreignKey": physId,
"properties.appointmentDate": { $gt: fixedDate }
}); // get all appointments after fixedDate
var patients = [];
appointments.forEach(function(appoint) {
patients.push(appoint.relation.patient);
})
return patient; // all patients in appointments
in node API
I have read the find method in doc, it use where filter to match value of specific field, but I think it is similar as the origin :-)
Appointment.find({
"relation.physician.foreignKey": physId,
"properties.appointmentDate": { gt: fixedDate }
})
and then you can use some method like _.forEach(underscore.js)to get the patients from the result
I wish it can solve your problem;