数据准备：第15节的数据
（1）求和（sum），aggs是固定写法，price_of_sum是取的名字。
GET /lib7/items/_search { "size":0, "aggs":{ "price_of_sum":{ "sum":{ "field":"price" } } } }
输出结果如下：
{ "took": 9, "timed_out": false, "_shards": { "total": 5, "successful": 5, "skipped": 0, "failed": 0 }, "hits": { "total": 5, "max_score": 0, "hits": [] }, "aggregations": { "price_of_sum": { "value": 145 } } }
（2）求最小值（min）
GET /lib7/items/_search { "size":0, "aggs":{ "price_of_min":{ "min":{ "field":"price" } } } }
输出结果如下：
{ "took": 51, "timed_out": false, "_shards": { "total": 5, "successful": 5, "skipped": 0, "failed": 0 }, "hits": { "total": 5, "max_score": 0, "hits": [] }, "aggregations": { "price_of_min": { "value": 25 } } }
（3）求最大值（max）
GET /lib7/items/_search { "size":0, "aggs":{ "price_of_max":{ "max":{ "field":"price" } } } }
输出结果如下：
{ "took": 14, "timed_out": false, "_shards": { "total": 5, "successful": 5, "skipped": 0, "failed": 0 }, "hits": { "total": 5, "max_score": 0, "hits": [] }, "aggregations": { "price_of_max": { "value": 50 } } }
（4）求平均值（avg）
GET /lib7/items/_search { "size":0, "aggs":{ "price_of_avg":{ "avg":{ "field":"price" } } } }
输出结果如下：
{ "took": 14, "timed_out": false, "_shards": { "total": 5, "successful": 5, "skipped": 0, "failed": 0 }, "hits": { "total": 5, "max_score": 0, "hits": [] }, "aggregations": { "price_of_avg": { "value": 36.25 } } }
（5）求基数（cardinality），互不相同的个数
GET /lib7/items/_search { "size":0, "aggs":{ "price_of_cardi":{ "cardinality":{ "field":"price" } } } }
执行结果如下：
{ "took": 38, "timed_out": false, "_shards": { "total": 5, "successful": 5, "skipped": 0, "failed": 0 }, "hits": { "total": 5, "max_score": 0, "hits": [] }, "aggregations": { "price_of_cardi": { "value": 4 } } }
（6）分组（terms）
GET /lib7/items/_search { "size":0, "aggs":{ "price_group_by":{ "terms":{ "field":"price" } } } }
输出结果如下：
{ "took": 45, "timed_out": false, "_shards": { "total": 5, "successful": 5, "skipped": 0, "failed": 0 }, "hits": { "total": 5, "max_score": 0, "hits": [] }, "aggregations": { "price_group_by": { "doc_count_error_upper_bound": 0, "sum_other_doc_count": 0, "buckets": [ { "key": 25, "doc_count": 1 }, { "key": 30, "doc_count": 1 }, { "key": 40, "doc_count": 1 }, { "key": 50, "doc_count": 1 } ] } } }
（7）对那些有唱歌兴趣的用户按年龄分组，并根据每组的平均年龄倒序排序，数据来自第12节
GET /lib3/user/_search { "size":0, "query":{ "match":{ "interests":"changge" } }, "aggs":{ "age_of_group":{ "terms":{ "field":"age", "order":{ "age_of_avg":"desc" } }, "aggs":{ "age_of_avg":{ "avg":{ "field":"age" } } } } } }
输出结果如下：
{ "took": 19, "timed_out": false, "_shards": { "total": 3, "successful": 3, "skipped": 0, "failed": 0 }, "hits": { "total": 3, "max_score": 0, "hits": [] }, "aggregations": { "age_of_group": { "doc_count_error_upper_bound": 0, "sum_other_doc_count": 0, "buckets": [ { "key": 29, "doc_count": 1, "age_of_avg": { "value": 29 } }, { "key": 23, "doc_count": 1, "age_of_avg": { "value": 23 } }, { "key": 20, "doc_count": 1, "age_of_avg": { "value": 20 } } ] } } }