Module order_by 

Ordering and distinct input types.

Hasura orders with order_by: [<table>_order_by!] where each entry maps a column to a direction drawn from one shared enum:

author(order_by: [{name: asc_nulls_last}, {id: desc}]) { id }

A list rather than a single object, because ordering is ordered: {name: asc, id: desc} is one object whose two keys have no defined precedence, and the client that wrote it meant name first.

The direction enum carries null placement, which the previous orderBy: ["name.asc"] strings could not express at all. In PostgreSQL nulls sort last ascending and first descending, so asc and asc_nulls_last mean the same thing and asc_nulls_first does not – which is exactly the case a client reaches for the enum to say.

distinct_on takes columns from a generated enum rather than strings, for the same reason the boolean expressions do: an unknown column should be refused by the client, not by the database.

Constants

DIRECTION_ENUM

The name of the shared direction enum.

Functions

aggregate_order_by_type_name

The name of the input for ordering a row by an aggregate of its children.

build_inputs

The ordering input and column enum for every table.

direction_enum

The shared direction enum.

direction_sql

The SQL for a direction, or None if it is not one.

function_order_by_type_name

The name of the input for ordering by one aggregate function’s results.

order_by_type_name

The name of a table’s ordering input.

select_column_type_name

The name of a table’s column enum.