data.read_in_loop: Query or get inside a for loop

Query or get inside a for loop.

Area 6, Reads and writes; not declinable; the next step is usually the agent's.

example

type Title = Text {    max_length: 80}entity Book {    id: Uuid    title: Title    subtitle: Title?    available: Bool}type BookNotFound = Failure {    kind: FailureKind.not_found}type Count = Int {    min: 0}action available_count(book_ids: List<Book.id>) fails BookNotFound -> Count {    var mut count: Count = 0    for book_id in book_ids {        var book: Book = attempt Book.get(book_id)        if (book.available) {            count = Count(count + 1)        }    }    return count}

jadpo checkcheck failed: 1 error, 1 file

error Book.get reads once for every item of the loop

--> main.jadpo:23:34

   |23 |         var book: Book = attempt Book.get(book_id)   |                                  ^^^^^^^^ inside `for`

reason: A read inside a loop makes one database query per item. Read the whole set with one query, testing the field with in a list of the values, before the loop.
next: Read the records with one query using in before the loop (agent)
rule: data.read_in_loop
help: https://jadpo.dev/docs/errors/data.read_in_loop