count(1)
select clssId,count(1) from student group by classId
{ "size":0, "aggs": { "group_by_classId": { "terms": { "field": "classId.keyword" } } } }
结果 key为classId doc_count 为count
size 0表示只看聚合结果不看搜索结果
{ "took": 82, "timed_out": false, "_shards": { "total": 5, "successful": 5, "skipped": 0, "failed": 0 }, "hits": { "total": 4, "max_score": 0, "hits": [] }, "aggregations": { "group_by_classId": { "doc_count_error_upper_bound": 0, "sum_other_doc_count": 0, "buckets": [ { "key": "2", "doc_count": 3 }, { "key": "5", "doc_count": 1 } ] } } }
count+avg
select clssId,count(1),avg(score) from student group by classId
{ "size":0, "aggs": { "group_by_classId": { "terms": { "field": "classId.keyword" }, "aggs": { "average_balance": { "avg": { "field": "score" } } } } } }
结果
{ "took": 95, "timed_out": false, "_shards": { "total": 5, "successful": 5, "skipped": 0, "failed": 0 }, "hits": { "total": 4, "max_score": 0, "hits": [] }, "aggregations": { "group_by_classId": { "doc_count_error_upper_bound": 0, "sum_other_doc_count": 0, "buckets": [ { "key": "2", "doc_count": 3, "average_balance": { "value": 53.333333333333336 } }, { "key": "5", "doc_count": 1, "average_balance": { "value": 10 } } ] } } }
聚合并排序
select clssId,count(1),avg(score) from student group by classId order by avg(score) desc
{ "size":0, "aggs": { "group_by_classId": { "terms": { "field": "classId.keyword", "order": { "average_score": "desc" } }, "aggs": { "average_score": { "avg": { "field": "score" } } } } } }