Understanding Hyperledger Composer Query Language

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enum UserRole {
  o ADMIN
  o MODERATOR
  o USER
}
participant User identified by id {
  o String id
  o String name
  o UserRole role
  o String[] hobbies
  --> Organization organization
}

participant Organization identified by id {
  o String id
  o String name
}

asset Product identified by id {
  o String id
  o String name
  o String description
  o Double quantity
  o DateTime createdAt
  --> Organization owner
}

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query Q1 {
  description: "Select all users based on role"
  statement:
      SELECT org.acme.User
          WHERE (role == "ADMIN")
}

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query Q1 {
    description: "Select all users based on role"
    statement:
        SELECT org.acme.User
            WHERE (role == _$role)
}

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query Q2 {
  description: "Select all users of an organization"
  statement:
      SELECT org.acme.User
          WHERE (organization == "resource:org.acme.Organization#1")
}

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query Q3 {
  description: "Select all products above the minimum quantity"
  statement:
      SELECT org.acme.Product
          WHERE (quantity > _$minimumThreshold)
}

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query Q4 {
  description: "Select all products above the minimum quantity of an organization"
  statement:
      SELECT org.acme.Product
          WHERE ((quantity > _$minimumThreshold) AND (owner == _$organization))
}

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query Q5 {
  description: "Select all products above the minimum quantity of an organization and order by quantity"
  statement:
      SELECT org.acme.Product
          WHERE ((quantity > _$minimumThreshold) AND (owner == _$organization))
              ORDER BY quantity
}

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query Q6 {
  description: "Select all users based on givien hobbies"
  statement:
      SELECT org.acme.User
          WHERE (hobbies CONTAINS ['driving', 'swimming']
}