Struct GenericForeignKey 

pub struct GenericForeignKey {
    pub content_type_id: i64,
    pub object_pk: i64,
}

“Generic foreign key” pair — a runtime pointer at any registered model’s row, formed by (content_type_id, object_pk). Sub-slice F.3 of the v0.15.0 ContentType plan.

Models embed it as two plain columns plus this struct used at the API surface — there’s no dedicated SQL type for “generic FK”, just the convention that content_type_id references rustango_content_types.id and object_pk is the target row’s primary key value. The framework hydrates targets via prefetch_generic.

Why not a typed T: Model field?

The whole point of the generic shape is that the target type isn’t known at compile time — a single audit log row, comment, activity-stream entry, or tag can point at any model. Typed FKs (ForeignKey<User>) are the right choice when the target type is fixed; GenericForeignKey is for the “could be anything” case Django’s contenttypes framework solves.

Fields

content_type_id: i64

FK to rustango_content_types.id. Identifies which model the object_pk lives in.

object_pk: i64

Primary key of the target row in the table named by the matching ContentType. Always i64 — the framework’s Auto<T> PK is i64 and non-Auto PKs that ride this path must be i64-coercible.

Implementations

impl GenericForeignKey

pub const fn new(content_type_id: i64, object_pk: i64) -> Self

Construct a GFK from a ContentType row + a target PK. The natural shape when the caller already has the ContentType in hand (audit log writer, comment-create handler, etc.).

pub async fn for_target<T: Model>( pool: &PgPool, object_pk: i64, ) -> Result<Self, ExecError>

Construct a GFK pointing at a row of T. Looks up T’s ContentType via the cached registry (for_model::<T>) — one DB round-trip the first time, free thereafter once memoization lands.

Errors

As ContentType::for_model.

Trait Implementations

impl Clone for GenericForeignKey

fn clone(&self) -> GenericForeignKey

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for GenericForeignKey

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for GenericForeignKey

fn eq(&self, other: &GenericForeignKey) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for GenericForeignKey

impl Eq for GenericForeignKey

impl StructuralPartialEq for GenericForeignKey