Menene mafi kyawun ayyuka na ƙirar GraphQL schema?

Question

IT Interview Practice · Accepted Answer

Kyakkyawan schema **abokin-ciniki ne ke tuƙa shi, nullable-by-default a gefuna, kuma mai iya juyawa ba tare da versions ba**. Yana yin ƙirar yankin (domain) da kalmomin da abokan ciniki suke amfani da su a zahiri, ba tebur ɗin database ɗinka ba.

## Nullability

Ka sa fili ya zama non-null (`!`) kawai lokacin da za ka iya *kullum* mayar da shi. Yin amfani da `!` fiye da kima tarko ne: idan fili na non-null ya sami kuskure, yana sa dukan parent object ɗinsa null, yana juya ƙaramar gazawa zuwa babbar farar wuri. Fifita nullable ga duk abin da ya dogara ga wani downstream service.

```graphql
type User {
  id: ID!             # truly always present
  email: String!      # required in your DB -> safe as non-null
  avatarUrl: String   # comes from an external service -> nullable, so its failure is isolated
}
```

## Suna & inputs

- Yi amfani da sunaye masu daidaituwa da siffatawa; booleans suna karantuwa kamar predicates (`isPublished`).
- Ba kowace mutation nau'in **`input`** guda ɗaya kuma ka mayar da nau'in **payload** — za ka iya ƙara filaye daga baya ba tare da karya sa hannun ba.

```graphql
input CreatePostInput { title: String!, body: String! }
type CreatePostPayload { post: Post!, errors: [UserError!]! }  # room to grow
type Mutation { createPost(input: CreatePostInput!): CreatePostPayload! }
```

## Juyawa ba tare da versioning ba

GraphQL yana guje wa URLs na `/v2`. Kana juyawa **ta ƙari**: ƙara filaye kyauta, kuma yi ritaya na tsofaffi da `@deprecated` yayin da abokan ciniki ke ƙaura.

```graphql
type User {
  fullName: String!
  name: String! @deprecated(reason: "Use fullName")   # keep serving until clients move off
}
```

Cirewa ko sake sunan fili shi ne kawai canjin karya na gaske, don haka ka tsara ta yadda ba za ka cika buƙatarsa ba. Har ila yau ka guji zubar da siffar DB (bayyana `fullName`, ba `first_name`/`last_name` ba idan abokan ciniki suna son fili guda).

## Me ya sa yake da muhimmanci

Waɗannan zaɓuɓɓuka su ne abin da ya raba schema da ke dawwama shekaru daga wanda abokan ciniki suke fama da shi. Masu tambayoyin hira suna amfani da wannan don auna **balagar ƙirar API** — musamman ciniki-cinikin nullability/error da tunanin juyawa-ta-ƙari, waɗanda suke na musamman ga GraphQL.

Nullability

Suna & inputs

Juyawa ba tare da versioning ba

Me ya sa yake da muhimmanci

Tambayoyi masu alaƙa