how to use $lookup stage in java with spring data mongodb? [duplicate]

how to use $lookup stage in java with spring data mongodb? [duplicate]

This question already has an answer here:

lookup in mongodb aggregation

1 answer

Up to last version of spring i have seen lot of stack over flow questions which shows there is no support for this operation in spring-data-mongodb is there any support for this operation in new spring-data-mongodb 1.10.0
db.orders.aggregate([
{
$lookup:
{
from: “inventory”,
localField: “item”,
foreignField: “sku”,
as: “inventory_docs”
}
}
])

Solutions/Answers:

Solution 1:

Lookup support has been there since 1.9 version.

LookupOperation lookupOperation = LookupOperation.newLookup().
                                   from("inventory").
                                   localField("item").
                                   foreignField("sku").
                                   as("inventory_docs");
Aggregation aggregation = Aggregation.newAggregation(lookupOperation);
List<BasicDBObject> results = mongoOperations.aggregate(aggregation, "orders", BasicDBObject.class).getMappedResults();

References

Related:  MongoDB node.js driver and monk