Struct Tracked 

pub struct Tracked<E: Entity> { /* private fields */ }

A loaded Entity that remembers its original column values so save persists only what changed. Deref targets the inner E, so reads and field mutations go straight through.

Implementations

impl<E: Entity> Tracked<E>

pub fn new(entity: E) -> Self

Wrap an in-hand entity; its current column values become the baseline.

pub async fn load<X, V>(exec: &X, pk: V) -> Result<Option<Self>>

where X: Executor, V: Into<Value>,

Load pk’s row and wrap it for tracking. None when no row matches.

pub fn changes(&self) -> Vec<(&'static str, Value)>

The columns whose value differs from the baseline (the dirty set), in the entity’s declared column order.

pub fn is_dirty(&self) -> bool

Whether any tracked column has changed since load / last save.

pub async fn save<X: Executor>(&mut self, exec: &X) -> Result<u64>

Persist the dirty columns with a single UPDATE … WHERE pk = ?, returning rows affected. A no-op returning 0 when nothing changed. On success the baseline is reset to the saved state, so a later save writes only newer changes (and an immediate re-save is a no-op).

pub fn get(&self) -> &E

Borrow the inner entity (also available through Deref).

pub fn into_inner(self) -> E

Unwrap, discarding tracking state.

Trait Implementations

impl<E: Entity> Deref for Tracked<E>

type Target = E

The resulting type after dereferencing.

fn deref(&self) -> &E

Dereferences the value.

impl<E: Entity> DerefMut for Tracked<E>

fn deref_mut(&mut self) -> &mut E

Mutably dereferences the value.