Struct SessionLoadQuery 

pub struct SessionLoadQuery<'a, C: CanisterKind, E: EntityKind<Canister = C>> { /* private fields */ }

SessionLoadQuery

Fluent, session-bound load query wrapper that keeps intent pure while routing execution through the DbSession boundary.

Implementations

impl<'a, C: CanisterKind, E: EntityKind<Canister = C>> SessionLoadQuery<'a, C, E>

pub const fn query(&self) -> &Query<E>

Return a reference to the underlying query intent.

pub fn by_key(self, key: impl Into<Key>) -> Self

Filter by primary key.

pub fn many<I>(self, keys: I) -> Self

where I: IntoIterator<Item = E::PrimaryKey>,

Load multiple entities by primary key.

Semantics:

• Equivalent to WHERE pk IN (…)
• Uses key-based access (ByKey / ByKeys)
• Missing keys are ignored in MissingOk mode
• Strict mode treats missing rows as corruption
• Empty input yields an empty result set

pub fn filter(self, predicate: Predicate) -> Self

Add a predicate, implicitly AND-ing with any existing predicate.

pub fn filter_expr(self, expr: FilterExpr) -> Result<Self, QueryError>

Apply a dynamic filter expression.

pub fn sort_expr(self, expr: SortExpr) -> Result<Self, QueryError>

Apply a dynamic sort expression.

pub fn order_by(self, field: impl AsRef<str>) -> Self

Append an ascending sort key.

pub fn order_by_desc(self, field: impl AsRef<str>) -> Self

Append a descending sort key.

pub fn limit(self, limit: u32) -> Self

Apply a load limit.

pub fn offset(self, offset: u32) -> Self

Apply a load offset.

pub fn explain(&self) -> Result<ExplainPlan, QueryError>

Explain this query without executing it.

pub fn plan(&self) -> Result<ExecutablePlan<E>, QueryError>

Plan this query into an executor-ready plan.

pub fn execute(&self) -> Result<Response<E>, QueryError>

Execute this query using the session’s policy settings.

pub fn exists(&self) -> Result<bool, QueryError>

Return whether any rows match this query.

pub fn is_empty(&self) -> Result<bool, QueryError>

Execute and return whether the response is empty.

pub fn count(&self) -> Result<u32, QueryError>

Execute and return the number of matching rows.

pub fn require_one(&self) -> Result<(), QueryError>

Execute and require exactly one row.

pub fn require_some(&self) -> Result<(), QueryError>

Execute and require at least one row.

pub fn row(&self) -> Result<Row<E>, QueryError>

pub fn try_row(&self) -> Result<Option<Row<E>>, QueryError>

pub fn rows(&self) -> Result<Vec<Row<E>>, QueryError>

pub fn entity(&self) -> Result<E, QueryError>

pub fn try_entity(&self) -> Result<Option<E>, QueryError>

pub fn entities(&self) -> Result<Vec<E>, QueryError>

pub fn group_count_by<K>( &self, key: impl Fn(&E) -> K, ) -> Result<HashMap<K, u32>, QueryError>

where K: Eq + Hash,

Execute and count entities grouped by the provided key selector.

pub fn one(&self) -> Result<E, QueryError>

Alias for entity.

pub fn one_opt(&self) -> Result<Option<E>, QueryError>

Alias for try_entity.

pub fn all(&self) -> Result<Vec<E>, QueryError>

Alias for entities.

pub fn key(&self) -> Result<Option<Key>, QueryError>

pub fn key_strict(&self) -> Result<Key, QueryError>

pub fn try_key(&self) -> Result<Option<Key>, QueryError>

pub fn keys(&self) -> Result<Vec<Key>, QueryError>

pub fn contains_key(&self, key: &Key) -> Result<bool, QueryError>

pub fn primary_key(&self) -> Result<E::PrimaryKey, QueryError>

pub fn try_primary_key(&self) -> Result<Option<E::PrimaryKey>, QueryError>

pub fn primary_keys(&self) -> Result<Vec<E::PrimaryKey>, QueryError>

pub fn views(&self) -> Result<Vec<View<E>>, QueryError>

pub fn view(&self) -> Result<View<E>, QueryError>

pub fn view_opt(&self) -> Result<Option<View<E>>, QueryError>

impl<C: CanisterKind, E: EntityKind<Canister = C>> SessionLoadQuery<'_, C, E>

where E::PrimaryKey: UnitKey,

pub fn only(self) -> Self

Load the singleton entity identified by the unit primary key ().

Semantics:

• Equivalent to WHERE pk = ()
• Uses key-based access (ByKey)
• Does not allow predicates
• MissingOk mode returns empty
• Strict mode treats missing row as corruption