Subscription filtering in GraphQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to subscribe to new messages with a filter on the channel ID.

GraphQL

subscription OnMessageAdded {
  messageAdded(channelId: [1]) {
    id
    content
  }
}

Drag options to blanks, or click blank then click option'

AchannelId

B123

C"123"

Dtrue

Attempts:

3 left

💡 Hint

Common Mistakes

Using a number without quotes for channelId.

Using a variable name instead of a string literal.

The channelId argument must be a string, so it needs quotes around the ID value.

2fill in blank

medium

Complete the filter argument to subscribe only to messages where the author is 'alice'.

GraphQL

subscription OnMessageAdded {
  messageAdded(filter: { author: { [1]: "alice" } }) {
    id
    content
  }
}

Drag options to blanks, or click blank then click option'

Aeq

Bneq

Ccontains

Din

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'neq' instead of 'eq' causes filtering for authors not equal to 'alice'.

Using 'contains' or 'in' when exact match is needed.

The 'eq' operator filters messages where author equals 'alice'.

3fill in blank

hard

Fix the error in the subscription filter to only get messages with content length greater than 100.

GraphQL

subscription OnMessageAdded {
  messageAdded(filter: { content: { length: { [1]: 100 } } }) {
    id
    content
  }
}

Drag options to blanks, or click blank then click option'

Alte

Blt

Ceq

Dgt

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'lt' or 'lte' filters for smaller content lengths.

Using 'eq' filters only exact length 100, not greater.

The 'gt' operator means 'greater than', which filters content length over 100.

4fill in blank

hard

Fill both blanks to subscribe to messages where the author is 'bob' and the content contains 'hello'.

GraphQL

subscription OnMessageAdded {
  messageAdded(filter: { author: { [1]: "bob" }, content: { [2]: "hello" } }) {
    id
    content
  }
}

Drag options to blanks, or click blank then click option'

Aeq

Bneq

Ccontains

Din

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'neq' for author filters out 'bob' messages.

Using 'eq' for content requires exact match, not substring.

Use 'eq' to match author exactly and 'contains' to check if content includes 'hello'.

5fill in blank

hard

Fill all three blanks to subscribe to messages where the channelId is 'general', the author is not 'eve', and the content length is less than 50.

GraphQL

subscription OnMessageAdded {
  messageAdded(filter: { channelId: [1], author: { [2]: "eve" }, content: { length: { [3]: 50 } } }) {
    id
    content
  }
}

Drag options to blanks, or click blank then click option'

A"general"

Bneq

Clt

Deq

Attempts:

3 left

💡 Hint

Common Mistakes

Not quoting the channelId string.

Using 'eq' instead of 'neq' to exclude author.

Using 'gt' instead of 'lt' for content length.

ChannelId must be the string 'general', author filter uses 'neq' to exclude 'eve', and content length uses 'lt' for less than 50.