Aliases & Fragments¶

This guide covers advanced GraphQL query composition using aliases, named fragments and inline fragments.

Aliases¶

Aliases rename fields in the result or query the same type multiple times:

Renaming Fields¶

{
  Person(name: "Alix") {
    fullName: name
    yearsOld: age
  }
}

Returns fullName and yearsOld instead of name and age.

Multiple Queries¶

Query the same type with different filters using aliases:

{
  alix: Person(name: "Alix") {
    name
    age
  }
  gus: Person(name: "Gus") {
    name
    age
  }
}

Aliasing Nested Fields¶

{
  Person(name: "Alix") {
    name
    closeFriends: friends {
      name
    }
  }
}

Named Fragments¶

Fragments define reusable sets of fields:

Defining and Using Fragments¶

query {
  Person(name: "Alix") {
    ...PersonFields
  }
}

fragment PersonFields on Person {
  name
  age
  email
}

The fragment's fields are included wherever the spread (...PersonFields) appears.

Fragments Across Multiple Queries¶

query {
  alix: Person(name: "Alix") {
    ...PersonInfo
  }
  gus: Person(name: "Gus") {
    ...PersonInfo
  }
}

fragment PersonInfo on Person {
  name
  age
  city
}

Inline Fragments¶

Inline fragments apply a type condition directly in the selection set:

{
  Person {
    name
    ... on Employee {
      department
      salary
    }
  }
}

This returns department and salary only for nodes that also have the Employee label.

Without Type Condition¶

Inline fragments can also be used without a type condition for grouping with directives:

{
  Person {
    name
    ... @include(if: true) {
      age
      email
    }
  }
}

Directives¶

Grafeo supports standard GraphQL directives:

@include¶

Conditionally include fields:

query GetPerson($withAge: Boolean!) {
  Person(name: "Alix") {
    name
    age @include(if: $withAge)
  }
}

@skip¶

Conditionally skip fields:

query GetPerson($hideEmail: Boolean!) {
  Person(name: "Alix") {
    name
    email @skip(if: $hideEmail)
  }
}

Python Example¶

import grafeo

db = grafeo.GrafeoDB()

# Create data
db.execute("INSERT (:Person {name: 'Alix', age: 30, city: 'Utrecht'})")
db.execute("INSERT (:Person {name: 'Gus', age: 25, city: 'Portland'})")

# Using aliases
result = db.execute_graphql("""
{
  alix: Person(name: "Alix") {
    name
    age
  }
  gus: Person(name: "Gus") {
    name
    age
  }
}
""")
for row in result:
    print(row)

# Using fragments
result = db.execute_graphql("""
query {
  Person(name: "Alix") {
    ...PersonDetails
  }
}

fragment PersonDetails on Person {
  name
  age
  city
}
""")
for row in result:
    print(row)

Feature Summary¶