query trader($address: ID!){
  accounts(where: {id: $address}) {
    id
    hasBorrowed
  }
}

function(data) {
  if (data == null || data.accounts == null) {
    return 0
  } else if (Array.isArray(data.accounts) && data.accounts.length == 0) {
    return 0
  } 
  return 1
}