Yaushe ya kamata a yi amfani da nested maimakon object?

Question

IT Interview Practice · Accepted Answer

Zaɓi `nested` idan sharuɗɗa da yawa dole su shafi element ɗaya a array. In ba haka ba, ƙimomi daga elements daban za su iya cika query tare ba da niyya ba.

## Samfur mai variants biyu

```json
{"variants":[{"color":"red","size":"S"},{"color":"blue","size":"L"}]}
```

Babu jan variant mai size L. Amma object mapping na yau da kullum yana shimfiɗa fields zuwa launuka da girma-girma da yawa, yana rasa alaƙar wane size ne na wane launi. Saboda haka query na ja da L zai iya dacewa da samfurin bisa kuskure.

## Nemi sharuɗɗan biyu a variant ɗaya

Map `variants` a matsayin `nested` da `color`/`size` a matsayin keyword. Sannan yi amfani da:

```json
{
  "query": {
    "nested": {
      "path": "variants",
      "query": {
        "bool": {
          "filter": [
            {"term":{"variants.color":"red"}},
            {"term":{"variants.size":"L"}}
          ]
        }
      }
    }
  }
}
```

Filters biyu yanzu suna gudana cikin nested element ɗaya, saboda haka samfurin misali ba ya dacewa. Canja L zuwa S kuma jan variant zai iya dacewa.

## Ka ɗauki kuɗin nested idan ana buƙata kawai

Nested elements suna ƙirƙirar ƙarin internal documents da queries masu tsada. Object na yau da kullum ya fi sauƙi idan ba a buƙatar kiyaye alaƙa cikin arrays. Gwada haɗe-haɗe masu inganci da waɗanda suka haɗa elements daban kafin yanke hukuncin cewa mapping yana aiki.

[Takardun hukuma](https://www.elastic.co/docs/reference/elasticsearch/mapping-reference/nested).

Samfur mai variants biyu

Nemi sharuɗɗan biyu a variant ɗaya

Ka ɗauki kuɗin nested idan ana buƙata kawai

Tambayoyi masu alaƙa