聚合分析对应数据库中的聚合函数。在 Elasticsearch 中使用 aggs 标签表示。
计算所有商品的价格总和
GET /store/product/_search
{
"aggs": {
"sum_price": {
"sum": {
"field": "price"
}
}
}
}
返回结果：
{
"took": 50,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 4,
"max_score": 1,
"hits": [
{
"_index": "store",
"_type": "product",
"_id": "2",
"_score": 1,
"_source": {
"name": "jiajieshi yagao",
"desc": "youxiao fangzhu",
"price": 25,
"producer": "jiajieshi producer",
"tags": [
"fangzhu"
]
}
},
{
"_index": "store",
"_type": "product",
"_id": "4",
"_score": 1,
"_source": {
"name": "special yagao",
"desc": "special meibai",
"price": 50,
"producer": "special yagao producer",
"tags": [
"meibai"
]
}
},
{
"_index": "store",
"_type": "product",
"_id": "1",
"_score": 1,
"_source": {
"name": "gaolujie yagao",
"desc": "gaoxiao meibai",
"price": 30,
"producer": "gaolujie producer",
"tags": [
"meibai",
"fangzhu"
]
}
},
{
"_index": "store",
"_type": "product",
"_id": "3",
"_score": 1,
"_source": {
"name": "zhonghua yagao",
"desc": "caoben zhiwu",
"price": 40,
"producer": "zhonghua producer",
"tags": [
"qingxin"
]
}
}
]
},
"aggregations": {
"sum_price": {
"value": 145
}
}
}
在返回结果中如果不想输出所有商品的记录，可以使用 size：0 进行控制：
GET /store/product/_search
{
"size": 0,
"aggs": {
"sum_price": {
"sum": {
"field": "price"
}
}
}
}
返回结果：
{
"took": 6,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 4,
"max_score": 0,
"hits": []
},
"aggregations": {
"sum_price": {
"value": 145
}
}
}
搜索最贵的商品
GET /store/product/_search
{
"size": 0,
"aggs": {
"max_price": {
"max": {
"field": "price"
}
}
}
}
返回结果：
{
"took": 1,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 4,
"max_score": 0,
"hits": []
},
"aggregations": {
"max_price": {
"value": 50
}
}
}
计算所有商品的平均价格
GET /store/product/_search
{
"size": 0,
"aggs": {
"avg_price": {
"avg": {
"field": "price"
}
}
}
}
返回结果：
{
"took": 7,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 4,
"max_score": 0,
"hits": []
},
"aggregations": {
"avg_price": {
"value": 36.25
}
}
}
统计每个标签下的商品数量
GET /store/product/_search
{
"size": 0,
"aggs": {
"group_by_tags": {
"terms": {
"field": "tags"
}
}
}
}
如果上来直接这么操作会报错：
{
"error": {
"root_cause": [
{
"type": "illegal_argument_exception",
"reason": "Fielddata is disabled on text fields by default. Set fielddata=true on [tags] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead."
}
],
"type": "search_phase_execution_exception",
"reason": "all shards failed",
"phase": "query",
"grouped": true,
"failed_shards": [
{
"shard": 0,
"index": "store",
"node": "-DEY-JneQYmg3g1leawBvA",
"reason": {
"type": "illegal_argument_exception",
"reason": "Fielddata is disabled on text fields by default. Set fielddata=true on [tags] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead."
}
}
]
},
"status": 400
}
需要先将 text field 的 fielddata 属性设置为 true：
PUT /store/_mapping/product
{
"properties": {
"tags": {
"type": "text",
"fielddata": true
}
}
}
接着再去执行上面的命令，顺利返回结果：
{
"took": 408,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 4,
"max_score": 0,
"hits": []
},
"aggregations": {
"group_by_tags": {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 0,
"buckets": [
{
"key": "fangzhu",
"doc_count": 2
},
{
"key": "meibai",
"doc_count": 2
},
{
"key": "qingxin",
"doc_count": 1
}
]
}
}
}
对名称中包含 "yagao" 的商品，统计每个标签下的商品数量
GET /store/product/_search
{
"size": 0,
"query": {
"match": {
"name": "yagao"
}
},
"aggs": {
"group_by_tags": {
"terms": {
"field": "tags"
}
}
}
}
返回结果：
{
"took": 1,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 4,
"max_score": 0,
"hits": []
},
"aggregations": {
"group_by_tags": {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 0,
"buckets": [
{
"key": "fangzhu",
"doc_count": 2
},
{
"key": "meibai",
"doc_count": 2
},
{
"key": "qingxin",
"doc_count": 1
}
]
}
}
}
先按照标签进行分组，再计算每组商品的平均价格
GET /store/product/_search
{
"size": 0,
"aggs": {
"group_by_tags": {
"terms": {
"field": "tags"
},
"aggs": {
"avg_price": {
"avg": {
"field": "price"
}
}
}
}
}
}
返回结果：
{
"took": 4,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 4,
"max_score": 0,
"hits": []
},
"aggregations": {
"group_by_tags": {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 0,
"buckets": [
{
"key": "fangzhu",
"doc_count": 2,
"avg_price": {
"value": 27.5
}
},
{
"key": "meibai",
"doc_count": 2,
"avg_price": {
"value": 40
}
},
{
"key": "qingxin",
"doc_count": 1,
"avg_price": {
"value": 40
}
}
]
}
}
}
先按照标签进行分组，再计算每组商品的平均价格，并按照价格倒序排序
GET /store/product/_search
{
"size": 0,
"aggs": {
"group_by_tags": {
"terms": {
"field": "tags",
"order": {
"avg_price": "desc"
}
},
"aggs": {
"avg_price": {
"avg": {
"field": "price"
}
}
}
}
}
}
返回结果：
{
"took": 5,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 4,
"max_score": 0,
"hits": []
},
"aggregations": {
"group_by_tags": {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 0,
"buckets": [
{
"key": "meibai",
"doc_count": 2,
"avg_price": {
"value": 40
}
},
{
"key": "qingxin",
"doc_count": 1,
"avg_price": {
"value": 40
}
},
{
"key": "fangzhu",
"doc_count": 2,
"avg_price": {
"value": 27.5
}
}
]
}
}
}
先按照指定的价格区间进行分组，然后在每组内按照标签进行分组，最后再计算每组的平均价格
{
"size": 0,
"aggs": {
"range_by_price": {
"range": {
"field": "price",
"ranges": [
{
"from": 0,
"to": 20
},
{
"from": 20,
"to": 40
},
{
"from": 40,
"to": 60
}
]
},
"aggs": {
"group_by_tags": {
"terms": {
"field": "tags"
},
"aggs": {
"avg_price": {
"avg": {
"field": "price"
}
}
}
}
}
}
}
}
返回结果：
{
"took": 2,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 4,
"max_score": 0,
"hits": []
},
"aggregations": {
"range_by_price": {
"buckets": [
{
"key": "0.0-20.0",
"from": 0,
"to": 20,
"doc_count": 0,
"group_by_tags": {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 0,
"buckets": []
}
},
{
"key": "20.0-40.0",
"from": 20,
"to": 40,
"doc_count": 2,
"group_by_tags": {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 0,
"buckets": [
{
"key": "fangzhu",
"doc_count": 2,
"avg_price": {
"value": 27.5
}
},
{
"key": "meibai",
"doc_count": 1,
"avg_price": {
"value": 30
}
}
]
}
},
{
"key": "40.0-60.0",
"from": 40,
"to": 60,
"doc_count": 2,
"group_by_tags": {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 0,
"buckets": [
{
"key": "meibai",
"doc_count": 1,
"avg_price": {
"value": 50
}
},
{
"key": "qingxin",
"doc_count": 1,
"avg_price": {
"value": 40
}
}
]
}
}
]
}
}
}
从结果中可以看出
{
"from": 20,
"to": 40
}
包含前面不包含后面，即：[20, 40)。
