Search a date range

Problem

You want to find documents which contain a date within a specified range.

Solution

You can search for query results in a range of dates using an index and a user-defined function.

The solution has several steps:

  1. Update your GraphQL schema

    This example needs the following types:

    graphqlCopied!
    type Todo {
  title: String!
  completed: Boolean
  completedDate: Date!
}

type Query {
  todosByDateRange(fromDate: Date!, toDate: Date!): [Todo!] @resolver(name: "todosByDateRange")
}

    This involves editing the GraphQL schema definition, wherever you have stored it, and then uploading the new schema in the Fauna Dashboard.

    When you import the above schema, the GraphQL API automatically creates a collection named Todo and a UDF named todosByDateRange.

    For more information about importing GraphQL schemas, see the GraphQL quick start.

  2. Create some documents to search

    graphqlCopied!
    mutation {
  Todo1: createTodo( data:{
    title: "Walk the dog"
    completed: true
    completedDate: "2022-01-10"
  }) {
    _id
  },
  Todo2: createTodo( data:{
    title: "Feed the cat"
    completed: true
    completedDate: "2022-01-12"
  }) {
    _id
  },
  Todo3: createTodo( data:{
    title: "Wash the car"
    completed: false
    completedDate: "2022-01-26"
  }) {
    _id
  }
}

  3. Create an index to search by date range

    Copied!
    ({
  name: "todos_by_completed_date",
  source: ("Todo"),
  values: [
    { field: ["data", "completedDate"] },
    { field: ["ref"] }
  ]
})
    {
  ref: ("todos_by_completed_date"),
  ts: 1643836096660000,
  active: true,
  serialized: true,
  name: 'todos_by_completed_date',
  source: ("Todo"),
  values: [ { field: [ 'data', 'completedDate' ] }, { field: [ 'ref' ] } ],
  partitions: 8
}
    Query metrics:

    •    bytesIn:   179

    •   bytesOut:   342

    • computeOps:     1

    •    readOps:     0

    •   writeOps:     4

    •  readBytes: 1,691

    • writeBytes:   922

    •  queryTime:  37ms

    •    retries:     0

  4. Update the sub function todosByDateRange

    Our schema defined a query called todosByDateRange, which, due to the @resolver directive directive, caused the GraphQL API to create a UDF with that name. However, the GraphQL API doesn’t know what should happen. We need to update the function to provide the appropriate operations:

    Copied!
    (
  ("todosByDateRange"),
  {
    body: (
      (
      ["fromDate", "toDate"],
        (
          (
            ["data"],
            (
              (
                (("todos_sorted_by_completed_date")),
                ("fromDate"),
                ("toDate")
              )
            )
          ),
          (["date", "ref"], (("ref")))
        )
      )
    )
  }
)
    {
  ref: ("todosByDateRange"),
  ts: 1646419021630000,
  name: 'todosByDateRange',
  body: ((["fromDate", "toDate"], ((["data"], (((("todos_sorted_by_completed_date")), ("fromDate"), ("toDate")))), (["date", "ref"], (("ref"))))))
}
    Query metrics:

    •    bytesIn:  359

    •   bytesOut:  458

    • computeOps:    1

    •    readOps:    0

    •   writeOps:    1

    •  readBytes:  289

    • writeBytes:  515

    •  queryTime: 21ms

    •    retries:    0

  5. Call the resolver

    graphqlCopied!
    query getTodos {
  todosByDateRange(
    fromDate: "2022-01-01",
    toDate: "2022-01-15"
  ) {
    title
    completed
    completedDate
  }
}

    The query generates the following results:

    {
  "data": {
    "todosByDateRange": [
      {
        "title": "Walk the dog",
        "completed": true,
        "completedDate": "2022-01-10"
      },
      {
        "title": "Feed the cat",
        "completed": true,
        "completedDate": "2022-01-12"
      }
    ]
  }
}

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