This commit introduces support for PostgreSQL generated columns by
adding two new field attributes to the `Georm` derive macro:
`#[georm(generated)]` and `#[georm(generated_always)]`.
The `#[georm(generated_always)]` attribute is for fields that are
always generated by the database, such as `GENERATED ALWAYS AS
IDENTITY` columns or columns with a `GENERATED ALWAYS AS (expression)
STORED` clause. These fields are now excluded from `INSERT` and
`UPDATE` statements, preventing accidental writes and ensuring data
integrity at compile time.
The `#[georm(generated)]` attribute is for fields that have a default
value generated by the database but can also be manually overridden,
such as `GENERATED BY DEFAULT AS IDENTITY` columns. These fields
behave similarly to `#[georm(defaultable)]` fields, allowing them to
be omitted from `INSERT` statements to use the database-generated
value.
For now, the behaviour is the same between `#[georm(generated)]` and
`#[georm(defaultable)]`, but the addition of the former now will be
useful for future features.
Key changes:
- Added `generated` and `generated_always` attributes to
`GeormFieldAttributes`.
- Introduced `GeneratedType` enum in the IR to represent the different
generation strategies.
- Modified the `create` and `update` query generation to exclude
fields marked with `#[georm(generated_always)]`.
- Integrated `#[georm(generated)]` fields with the existing
defaultable struct logic.
- Added validation to prevent conflicting attribute usage, namely
`#[georm(generated)]` and `#[georm(generated_always)]` on the same
field.
Implements #3
Add support for entities with composite primary keys using multiple
#[georm(id)] fields. Automatically generates {EntityName}Id structs for
type-safe composite key handling.
Features:
- Multi-field primary key detection and ID struct generation
- Full CRUD operations (find, create, update, delete, create_or_update)
- Proper SQL generation with AND clauses for composite keys
- Updated documNtation in README and lib.rs
Note: Relationships not yet supported for composite key entities
Currently, all methods declared in the Georm trait are available.
If a struct has an ID pointing towards another entity, the user can
create a get method to get the entity pointed at from the database
too (local one-to-one relationship).
I still need to implement remote one-to-one relationships (one-to-one
relationships when the ID of the remote object is not available
locally).
I still need to also test and debug one-to-many relationships (ID of
the remote entiies not available locally) and many-to-many
relationships (declared in a dedicated table).
For now, IDs in all cases are simple types recognized by SQLx that are
not arrays. Options are only supported when explicitely specified for
one-to-one relationships.
