predavanja/Events.GraphQL/graphql-query-examples.md

# GraphQL Query Examples

The project exposes the GraphQL endpoint at `/graphql`, and in development GraphiQL is available at `/`.

## Defined queries

The following queries are defined in `Queries.cs`:

- `countries`
- `sports`
- `people`
- `peoplePage(pageNumber, pageSize)`
- `events`
- `eventsForDate(date)`
- `registrations`

The `countries`, `sports`, `people`, `events`, `eventsForDate`, and `registrations` queries support:

- paging via `first`, `after`, `last`, `before`
- filtering via the `where` argument
- sorting via the `order` argument
- `totalCount` because it is enabled in paging options

## Basic examples

### 1. Get countries

```graphql
query {
  countries(first: 10) {
    totalCount
    nodes {
      code
      alpha3
      name
    }
  }
}
```

### 2. Get sports

```graphql
query {
  sports(first: 10, order: [{ name: ASC }]) {
    nodes {
      id
      name
    }
  }
}
```

### 3. Get people

```graphql
query {
  people(first: 10) {
    totalCount
    nodes {
      id
      firstName
      lastName
      email
      city
      birthDate
      countryCode
    }
  }
}
```

### 4. Get events

```graphql
query {
  events(first: 10, order: [{ eventDate: DESC }]) {
    nodes {
      id
      name
      eventDate
    }
  }
}
```

### 5. Get registrations

```graphql
query {
  registrations(first: 10) {
    nodes {
      id
      registeredAt
      personId
      sportId
      eventId
    }
  }
}
```

## Filtering and sorting examples

### 6. Countries whose name contains "Bos"

```graphql
query {
  countries(
    first: 10
    where: { name: { contains: "Bos" } }
    order: [{ name: ASC }]
  ) {
    nodes {
      code
      name
    }
  }
}
```

### 7. People from a specific country

```graphql
query {
  people(
    first: 10
    where: { countryCode: { eq: "HR" } }
    order: [{ lastName: ASC }, { firstName: ASC }]
  ) {
    totalCount
    nodes {
      id
      firstName
      lastName
      city
      countryCode
    }
  }
}
```

### 8. People born after a given date

```graphql
query {
  people(
    first: 10
    where: { birthDate: { gt: "2000-01-01" } }
    order: [{ birthDate: DESC }]
  ) {
    nodes {
      id
      firstName
      lastName
      birthDate
    }
  }
}
```

### 9. Events for an exact date

```graphql
query {
  eventsForDate(date: "2026-06-15", first: 20) {
    totalCount
    nodes {
      id
      name
      eventDate
    }
  }
}
```

### 10. Events whose name contains a word

```graphql
query {
  events(
    first: 10
    where: { name: { contains: "Open" } }
    order: [{ eventDate: ASC }]
  ) {
    nodes {
      id
      name
      eventDate
    }
  }
}
```

### 11. Registrations with nested data

```graphql
query {
  registrations(first: 10, order: [{ registeredAt: DESC }]) {
    nodes {
      id
      registeredAt
      person {
        id
        firstName
        lastName
      }
      sport {
        id
        name
      }
      event {
        id
        name
        eventDate
      }
    }
  }
}
```

## Paging examples

### 12. `pageInfo` for cursor paging

```graphql
query {
  people(first: 5, order: [{ id: ASC }]) {
    totalCount
    pageInfo {
      hasNextPage
      endCursor
    }
    nodes {
      id
      firstName
      lastName
    }
  }
}
```

### 13. Next page using a cursor

```graphql
query {
  people(first: 5, after: "PUT_END_CURSOR_HERE") {
    pageInfo {
      hasNextPage
      endCursor
    }
    nodes {
      id
      firstName
      lastName
    }
  }
}
```

### 14. Custom page query `peoplePage`

This query does not use cursor paging. It uses classic `pageNumber` and `pageSize`.

```graphql
query {
  peoplePage(pageNumber: 2, pageSize: 5) {
    totalCount
    pageNumber
    pageSize
    items {
      id
      firstName
      lastName
      email
    }
  }
}
```

## Examples with variables

### 15. `eventsForDate` with variables

```graphql
query EventsForDate($date: Date!) {
  eventsForDate(date: $date, first: 20) {
    nodes {
      id
      name
      eventDate
    }
  }
}
```

Variables:

```json
{
  "date": "2026-06-15"
}
```

### 16. `peoplePage` with variables

```graphql
query PeoplePage($pageNumber: Int!, $pageSize: Int!) {
  peoplePage(pageNumber: $pageNumber, pageSize: $pageSize) {
    totalCount
    pageNumber
    pageSize
    items {
      id
      firstName
      lastName
    }
  }
}
```

Variables:

```json
{
  "pageNumber": 1,
  "pageSize": 10
}
```

## Existing mutations

Even though this document focuses on queries, the project also defines these mutations for the `Event` entity:

- `addEvent(input)`
- `updateEvent(id, input)`
- `deleteEvent(id)`

### 17. Add an event

```graphql
mutation {
  addEvent(input: { name: "Street Basketball 2026", eventDate: "2026-07-01" }) {
    id
    name
    eventDate
  }
}
```

### 18. Update an event

```graphql
mutation {
  updateEvent(
    id: 1
    input: { name: "Street Basketball 2026", eventDate: "2026-07-02" }
  ) {
    id
    name
    eventDate
  }
}
```

### 19. Delete an event

```graphql
mutation {
  deleteEvent(id: 1)
}
```

## Fields by type

Useful fields visible from the models:

- `Country`: `code`, `alpha3`, `name`, `translations`
- `Sport`: `id`, `name`
- `Person`: `id`, `firstName`, `lastName`, `firstNameTranscription`, `lastNameTranscription`, `addressLine`, `postalCode`, `city`, `addressCountry`, `email`, `contactPhone`, `birthDate`, `documentNumber`, `countryCode`
- `Event`: `id`, `name`, `eventDate`
- `Registration`: `id`, `personId`, `sportId`, `eventId`, `registeredAt`

## Source

Examples are based on the implementation in:

- `Events.GraphQLServer/SetupGraphQL/Queries.cs`
- `Events.GraphQLServer/SetupGraphQL/Mutations.Event.cs`
- `Events.GraphQLServer/SetupGraphQL/PeoplePage.cs`
- `Events.GraphQLServer/SetupGraphQL/EventInput.cs`
- `Events.EF/Models/*.cs`