How to Use MongoDB $aggregate with $push for Multiple Fields in Java Spring Data

How can I use MongoDB's $aggregate operator with $push to combine multiple fields within Java Spring Data?

List<AggregationOperation> operations = Arrays.asList(
    Aggregation.group("field1", "field2").push("field3").as("pushedFields")
);

Using MongoDB's $aggregate and $push operators in Java Spring Data allows developers to efficiently group data and consolidate multiple field values into an array. This is particularly useful for scenarios where you want to organize related entries under a common key.

List<AggregationOperation> operations = Arrays.asList(
    Aggregation.group("category").push("item").as("items")
);
AggregationResults<YourResultClass> results = mongoTemplate.aggregate(
    Aggregation.newAggregation(operations), "collectionName", YourResultClass.class
);

Causes

• Lack of understanding of aggregation framework in MongoDB.
• Misconfiguration of aggregation operations while using Spring Data.
• Inadequate knowledge of how to handle multiple fields in aggregation.

Solutions

• Use the Aggregation framework in Spring Data MongoDB to manage multiple fields effectively.
• Implement the .group() operation to specify the fields for aggregation.
• Utilize the .push() operator to gather data from multiple fields into a single array.

Mistake: Not grouping the correct fields in the aggregation operation.

Solution: Ensure that you specify the right fields in .group() for the desired aggregation context.

Mistake: Forgetting to define the output structure of the aggregation result.

Solution: Define an appropriate result class that matches the output of the aggregation.

Mistake: Using incorrect collection names in the aggregate call.

Solution: Double-check the collection name string in the aggregation query to ensure it matches your MongoDB schema.