Trait diesel::associations::Identifiable
source · pub trait Identifiable: HasTable {
type Id: Hash + Eq;
// Required method
fn id(self) -> Self::Id;
}
Expand description
This trait indicates that a struct represents a single row in a database table.
This must be implemented to use associations.
Additionally, implementing this trait allows you to pass your struct to update
(update(&your_struct)
is equivalent to
update(YourStruct::table().find(&your_struct.primary_key())
).
This trait is usually implemented on a reference to a struct, not on the struct itself. It can be derived.
Required Associated Types§
Required Methods§
sourcefn id(self) -> Self::Id
fn id(self) -> Self::Id
Returns the identifier for this record.
This takes self
by value, not reference.
This is because composite primary keys
are typically stored as multiple fields.
We could not return &(String, String)
if each string is a separate field.
Because of Rust’s rules about specifying lifetimes,
this means that Identifiable
is usually implemented on references
so that we have a lifetime to use for Id
.