概述
继续跟中华石杉老师学习ES，第46篇
课程地址： https://www.roncoo.com/view/55
官方说明
Cardinality Aggregation：戳这里
es中的去重，cartinality metric，对每个bucket中的指定的field进行去重，取去重后的count，类似于count(distcint)
示例
代码语言：javascript复制GET /tvs/sales/_search
{
"aggs": {
"month":{
"date_histogram": {
"field": "sold_date",
"interval": "month"
},
"aggs": {
"distinct_brand_cnt": {
"cardinality": {
"field": "brand"
}
}
}
}
},
"size": 0
}返回：
代码语言：javascript复制{
"took": 8,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"skipped": 0,
"failed": 0
},
"hits": {
"total": 8,
"max_score": 0,
"hits": []
},
"aggregations": {
"month": {
"buckets": [
{
"key_as_string": "2016-05-01T00:00:00.000Z",
"key": 1462060800000,
"doc_count": 1,
"distinct_brand_cnt": {
"value": 1
}
},
{
"key_as_string": "2016-06-01T00:00:00.000Z",
"key": 1464739200000,
"doc_count": 0,
"distinct_brand_cnt": {
"value": 0
}
},
{
"key_as_string": "2016-07-01T00:00:00.000Z",
"key": 1467331200000,
"doc_count": 1,
"distinct_brand_cnt": {
"value": 1
}
},
{
"key_as_string": "2016-08-01T00:00:00.000Z",
"key": 1470009600000,
"doc_count": 1,
"distinct_brand_cnt": {
"value": 1
}
},
{
"key_as_string": "2016-09-01T00:00:00.000Z",
"key": 1472688000000,
"doc_count": 0,
"distinct_brand_cnt": {
"value": 0
}
},
{
"key_as_string": "2016-10-01T00:00:00.000Z",
"key": 1475280000000,
"doc_count": 1,
"distinct_brand_cnt": {
"value": 1
}
},
{
"key_as_string": "2016-11-01T00:00:00.000Z",
"key": 1477958400000,
"doc_count": 2,
"distinct_brand_cnt": {
"value": 1
}
},
{
"key_as_string": "2016-12-01T00:00:00.000Z",
"key": 1480550400000,
"doc_count": 0,
"distinct_brand_cnt": {
"value": 0
}
},
{
"key_as_string": "2017-01-01T00:00:00.000Z",
"key": 1483228800000,
"doc_count": 1,
"distinct_brand_cnt": {
"value": 1
}
},
{
"key_as_string": "2017-02-01T00:00:00.000Z",
"key": 1485907200000,
"doc_count": 1,
"distinct_brand_cnt": {
"value": 1
}
}
]
}
}
}我们来看下原始数据：
来看下我们的统计结果，找个 2016-11
统计正确。
