How to get data from different schema in Nodejs - node.js

Question

I have two schemas called employees (parent) and assessments(child)
Every assessment will have a pass percentage of employee id
so I have results like this
employees : [
{
"_id": 12345,
"name": "David",
"evaluated": false
},
{
"_id": 12346,
"name": "Miller",
"evaluated": false
}
]
Second Schema
assessments: [
{
"assessment_type": "basic",
"employee_id": 12345,
"qualified": true
},
{
"assessment_type": "advanced",
"employee_id": 12345,
"qualified": false
},
{
"assessment_type": "basic",
"employee_id": 12346,
"qualified": true
},
{
"assessment_type": "advanced",
"employee_id": 12346,
"qualified": true
}
]
So I want to get the employees with evaluated based on assessments qualified is true
can you please tell me what is the best approach for this?

Answer 1

Here is an example where we sort the employees by the assements they succeeded.
const employees = [{
_id: 12345,
name: 'David',
evaluated: false,
}, {
_id: 12346,
name: 'Miller',
evaluated: false,
}];
const assessments = [{
assessment_type: 'basic',
employee_id: 12345,
qualified: true,
}, {
assessment_type: 'advanced',
employee_id: 12345,
qualified: false,
}, {
assessment_type: 'basic',
employee_id: 12346,
qualified: true,
}, {
assessment_type: 'advanced',
employee_id: 12346,
qualified: true,
}];
// Loop at the employees
const sortByAssessment = employees.reduce((tmp, x) => {
// Get all the assessment about the employee
const employeeAssessment = assessments.filter(y => y.employee_id === x._id);
// Deal with each assessment
employeeAssessment.forEach((y) => {
// Only do something about successfull assessments
if (y.qualified) {
// In case this is the first time we are dealing with the assessment_type
// create an array where we are going to insert employees informations
tmp[y.assessment_type] = tmp[y.assessment_type] || [];
// Push the name of the employee inside of the assessment type array
tmp[y.assessment_type].push(x.name);
}
});
return tmp;
}, {});
console.log(sortByAssessment);

Answer 2

you can do 2 things join with $look up or populate with employee id
assessments.aggregate([
{
'$lookup': {
'from': 'employees',
'localField': 'employee_id',
'foreignField': '_id',
'as': 'datas'
}
},
{ "$unwind": "$datas" },
].exec(function(err,result){
console.log(result)
});
2nd way
//assessments your model name
assessments.populate('employee_id').exec(function(err,result){
console.log(result);
});