How to use MongoDB Aggegation GroupOperation Method in JAVA

Question

I have a query and using count based on condition while in java I am using Aggregation GroupOperation Object. so how can write this statement in JAVA? Sample Query :

{
    $group: {
      _id: {
        "categoryCode": "$categoryCode",
        "categoryName": "$categoryName"
      },
      "cat_count": {
        $sum: {
          $cond: [{ $eq: ["$cat_type", "A"] }, 1, 0]
        }
      }
    }
  }

Answer 1

You can use Aggregation classes from org.springframework.data.mongodb.core.aggregation package to write this query.

ConditionalOperators.Cond cond = ConditionalOperators.Cond.when(ComparisonOperators.Eq.valueOf("$cat_type").equalToValue("A"))
            .then(1)
            .otherwise(0);
GroupOperation groupOperation = Aggregation.group("categoryCode", "categoryName").sum(cond).as("cat_count");

Now use this groupOperation with mongotemplate to execute query.