创建集合“test”，并向其中插入一个文档:{"_id":NumberLong(1),"pointsBalances":[{"period":"2020","startDate":ISODate("2020-01-01T00:00:00.000Z"),"endDate":ISODate("2020-12-31T23:59:59.999Z"),"value":0},{"period":"2019","startDate":ISODate("2019-01-01T00:00:00.000Z"),"endDate":ISODate("2019-12-31T23:59:59.999Z"),"v