关于聚合:Elasticsearch-实现-sql-count-distinct-的功能qbit

前言

• 本文对 Elasticsearch 7.17 实用

count distinct

• 单字段

  "aggs": {  "card": {    "cardinality": {      "field": "type"    }  }}

• 多字段

  "aggs": {  "multi_field_cardinality": {    "cardinality": {      "script": "doc['type'].value + '#' + doc['color'].value"    }  }}

  OR

  // 这个写法比下面的写法效率高很多{"runtime_mappings": {  "type_and_color": {    "type": "keyword",    "script": "emit(doc['type'].value + '#' + doc['color'].value)"  }},"aggs": {  "type_and_color": {    "cardinality": {      "field": "type_and_color"    }  }}}

相干浏览

• Elasticsearch Cardinality aggregation 官网文档：https://www.elastic.co/guide/en/elasticsearch/reference/7.17/...
• StackOverflow：Getting cardinality of multiple fields?

本文出自 qbit snap