mongodb的查询操作

1、条件匹配：MatchOperation

MatchOperation matchOperation = Aggregation.match(new Criteria().where("area_code").is(areaCode));

2、分组计数：GroupOperation + count

GroupOperation groupSource_typeOperation = Aggregation.group("source_type", "satisfied_degree")
    .count().as("count").first("source_type").as("source_type");

3、分组求和：GroupOperation + sum

GroupOperation groupDeptOperation = groupDeptOperation = Aggregation.group("dept_name")
    .sum("evaluate_quantity").as("evaluate_quantity").first("dept_name").as("dept_name");

4、排序：SortOperation

SortOperation sortOperation = Aggregation.sort(new Sort(Direction.DESC,"evaluate_quantity"));

5、跳过：SkipOperation

SkipOperation skipOperation = Aggregation.skip(10);

6、限制查多少个：LimitOperation

LimitOperation limitOperation = Aggregation.limit(10)；

7、执行查询

注意，Operation的顺序一定要写对，不然查出来有差异，是按照add进list的顺序执行，直接写在入参中也是一样

List<AggregationOperation> operations = new ArrayList<>();
operations.add(matchDeptOperation);
operations.add(groupDeptOperation);
operations.add(skipOperation );
operations.add(limitOperation);
AggregationResults<Map> aggregate = mongoTemplate.aggregate(Aggregation.newAggregation(operations), EvaluateConstant.EVALUATE_COLLECTION, Map.class);