Struct ManyToManyManager 

pub struct ManyToManyManager<S: Model, T: Model> { /* private fields */ }

Accessor for one many-to-many relation of one source object (post.tags(&db)). Generated accessors construct it; its query and mutation methods (all, add, remove, clear, set) run on db.

Implementations

impl<S: Model, T: Model> ManyToManyManager<S, T>

pub fn queryset(&self) -> QuerySet<T>

Lazy queryset over the related objects (WHERE pk IN (SELECT target FROM through WHERE source = ..)); filter or order it further.

pub async fn all(&self) -> Result<Vec<T>, OrmError>

Every related object.

Errors

Capability or backend errors.

pub async fn count(&self) -> Result<u64, OrmError>

Number of related objects.

Errors

Capability or backend errors.

pub async fn contains(&self, object: &T) -> Result<bool, OrmError>

Whether object is related.

Errors

Capability or backend errors.

pub async fn add<'a>( &self, objects: impl IntoIterator<Item = &'a T>, ) -> Result<(), OrmError>

Relate objects (already related ones are skipped).

Errors

Capability or backend errors (BackendError::Constraint when a target does not exist).

pub async fn add_pks( &self, keys: impl IntoIterator<Item = T::Pk>, ) -> Result<(), OrmError>

add by primary key.

Errors

As add.

pub async fn remove<'a>( &self, objects: impl IntoIterator<Item = &'a T>, ) -> Result<u64, OrmError>

Unrelate objects; returns the number of links removed.

Errors

Capability or backend errors.

pub async fn remove_pks( &self, keys: impl IntoIterator<Item = T::Pk>, ) -> Result<u64, OrmError>

remove by primary key.

Errors

As remove.

pub async fn clear(&self) -> Result<u64, OrmError>

Unrelate everything; returns the number of links removed.

Errors

Capability or backend errors.

pub async fn set<'a>( &self, objects: impl IntoIterator<Item = &'a T>, ) -> Result<(), OrmError>

Make objects exactly the related set: add the missing, remove the rest.

Errors

Capability or backend errors; nothing changes on failure.

pub async fn set_pks( &self, keys: impl IntoIterator<Item = T::Pk>, ) -> Result<(), OrmError>

set by primary key.

Errors

As set.

impl<S: Model, T: Model> ManyToManyManager<S, T>

pub fn new(db: &Db, meta: &'static ManyToManyMeta, source_pk: Value) -> Self

Manager for relation meta of the object whose key is source_pk.

pub fn db(&self) -> &Db

Database handle.

pub fn meta(&self) -> &'static ManyToManyMeta

Relation metadata.

pub fn source_pk(&self) -> &Value

Key of the source object.