Enum RelationKey 

pub enum RelationKey<'a> {
    Local(&'a ColumnName),
    Direct(&'a ColumnName),
    Through(&'a Through),
}

A relation’s key, viewed uniformly across joins and aggregates — the three physical shapes a “these tables connect” fact can take. Traversal code (document SQL, reverse resolution) matches on this instead of caring whether the relation is a join or an aggregate.

Variants

Local(&'a ColumnName)

The parent row holds the key: parent.column → target.primary_key (a belongs_to).

Direct(&'a ColumnName)

The related rows hold the key: target.foreign_key → parent.pk (a has_one/has_many, or a direct-keyed aggregate).

Through(&'a Through)

Both sides connect through a junction table.

Trait Implementations

impl<'a> Clone for RelationKey<'a>

fn clone(&self) -> RelationKey<'a>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a> Copy for RelationKey<'a>

impl<'a> Debug for RelationKey<'a>

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

Formats the value using the given formatter.