query.condition_unsupported: Query condition is not one an index can serve

Query condition is not one an index can serve.

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}query books_after(title: Book.title) -> List<Book> {    from: Book    where: Book.title > title    order: [Book.title asc]    limit: 20}

jadpo checkcheck failed: 1 error, 1 file

error Book.title > title isn't a condition a query can use

--> main.jadpo:14:12

   |14 |     where: Book.title > title   |            ^^^^^^^^^^^^^^^^^^ not an indexable condition

reason: > orders numbers, times, dates, durations and quantities, as it does in a body, and Book.title is Title.
next: Compare Book.title with ==, != or in (agent)
rule: query.condition_unsupported
help: https://jadpo.dev/docs/errors/query.condition_unsupported

A standard operation stands where a field does only when it has an exact SQL form ("Operations in conditions"). text.lower has none, since PostgreSQL's would follow the database's collation:

example

type Title = Text {    max_length: 80}entity Book {    id: Uuid    title: Title}query books_titled(title: Book.title) -> List<Book> {    from: Book    where: text.lower(Book.title) == title    order: [Book.title asc]    limit: 20}

jadpo checkcheck failed: 1 error, 1 file

error text.lower(Book.title) == title isn't a condition a query can use

--> main.jadpo:12:12

   |12 |     where: text.lower(Book.title) == title   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not an indexable condition

reason: text.lower has no SQL form, an expression PostgreSQL works out exactly as the code does (area 19, "SQL forms"), so the database can't decide this condition.
next: Compare Book.title itself, or keep what the condition needs in a field of its own (agent)
rule: query.condition_unsupported
help: https://jadpo.dev/docs/errors/query.condition_unsupported