spring mongoTemplate bulk find - spring

Question

I've got an employee collection that looks like:
{
_id
company_id
job_type
name
age
created_at
...
}
I've for a list of company_ids and for each of them I want to get the latest 3 employees for job_type="part_time" and the latest 3 for job_type="intern" (according to the created_at field)
How can I do such a thing using one call?
An answer with mongoTemplate.bulkOps will also be valid.

Answer 1

To get the latest you can use the auto created _id field it has a date embedded in it. Assuming the name of your collection is employee you can use the following aggregation:
db.employee.aggregate([
{
$facet: {
"part_time": [
{
$match: {
"job_type": "part_time"
}
},
{
$match: {
"company_id": "id_from_your_list"
}
},
{ $sort: { "_id": 1 } },
{
$limit: 3
}
],
"intern": [
{
$match: {
"job_type": "intern"
}
},
{
$match: {
"company_id": "id_from_your_list"
}
},
{ $sort: { "_id": 1 } },
{
$limit: 3
}
]
}
}])
I assume that you are using spring data mongodb you can execute this aggregation operation using MongoTemplate helper.
FacetOperation facetOperation = facet().and(match(Criteria.where("job_type").is("part_time")),match(Criteria.where("company_id").is("company_id_from_your_list")),
sort(Sort.Direction.ASC, "_id"),
limit(3)).as("part_time")
.and(match(Criteria.where("job_type").is("intern")),match(Criteria.where("company_id").is("company_id_from_your_list")),
sort(Sort.Direction.ASC, "_id"),
limit(3)).as("intern");
mongoTemplate.aggregate(Aggregation.newAggregation(facetOperation), "employee", Document.class).getUniqueMappedResult();