Aggregations about rel HOT 2 CLOSED

Just copy-pasting the discussion related to this issue:

thelinuxlich — We will group automatically if the user adds in the graphql query additional fields besides the common aggregations

query {
  findNotes {
    text
    count(of: NoteFields.id)
  }
}

Will automatically group by text, count(id)

from rel.

Just added the 5 essential aggregations to Rel: count, max, sum, avg and min.

The codegen will generate a enum containing all fields of each model to input on count, and a enum containing all fields of number type(including scalars) for the other 4 aggregations.

If the user pass additional fields on query, Rel will automatically GROUP the result, example:

Query {
   findTodos(filter: { a: { gt: 1 } }) {
      a
      sum(of: TodoFields.b)
   }
}

Is equivalent to GROUP(a, sum(b))

from rel.