Query all data and display all fields from an Operation

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1

Hi guys I’m currently learning GraphQL using ApolloServer sandbox.

i have function or operation where it queries a student data from the server.

{"operationName":"getStudent",
       "variables":{
               "id":"studentIDhere"
},
query getStudent($id: ID!) {
  student(_id: $id) {
    _id
    studentInfo {
      Firstname
      Surname
      Section
      Course
    }

How do I display all students and all of its data from a single query? Sorry if you dont understand my question english is not my first language I hope my question make sense