elasticsearch 实现聚合后两个字段相除相加相减相乘，运算

Posted 2021-09-13 那页阳光

有个需求，在sql中的计算方式是：

sum(cost) / 100 / sum(view_count) * 1000

统计出平均千次展现均价，成本按分存储。

在es中需要聚合cost和view_count 之后再运算。折腾了半天，记录下：

"aggs" => [
    \'total_cost_count\' => [
        \'sum\' => [
            \'field\' => \'cost\'
        ]
    ],
    \'total_view_count\' => [
        \'sum\' => [
            \'field\' => \'view_count\'
        ]
    ],
    \'(total_cost / total_view)\' => [
        \'bucket_script\' => [
            \'buckets_path\' => [
                \'cost\' => \'total_cost_count\',
                \'view_count\' => \'total_view_count\',
            ],
            \'script\' => [
                \'source\' => "params.cost / params.unit / params.view_count * params.days",
                \'params\' => [
                    \'unit\' => 100,
                    \'days\' => 1000,
                ]
            ]
        ]
    ]
],

调试过程中报错信息：

• Only sibling pipeline aggregations are allowed at the top level

  • 在顶层只允许兄弟管道聚合。也就是聚合运算只能在同一个桶内。

参考文档：https://www.elastic.co/guide/en/elasticsearch/painless/7.13/painless-bucket-script-agg-context.html