Trait diesel::connection::LoadConnection
source · pub trait LoadConnection<B = DefaultLoadingMode>: Connection {
type Cursor<'conn, 'query>: Iterator<Item = QueryResult<<Self as LoadConnection<B>>::Row<'conn, 'query>>>
where Self: 'conn;
type Row<'conn, 'query>: Row<'conn, Self::Backend>
where Self: 'conn;
// Required method
fn load<'conn, 'query, T>(
&'conn mut self,
source: T,
) -> QueryResult<Self::Cursor<'conn, 'query>>
where T: Query + QueryFragment<Self::Backend> + QueryId + 'query,
Self::Backend: QueryMetadata<T::SqlType>;
}
Expand description
The specific part of a Connection
which actually loads data from the database
This is a separate trait to allow connection implementations to specify different loading modes via the generic parameter.
Required Associated Types§
sourcetype Cursor<'conn, 'query>: Iterator<Item = QueryResult<<Self as LoadConnection<B>>::Row<'conn, 'query>>>
where
Self: 'conn
type Cursor<'conn, 'query>: Iterator<Item = QueryResult<<Self as LoadConnection<B>>::Row<'conn, 'query>>> where Self: 'conn
The cursor type returned by LoadConnection::load
Users should handle this as opaque type that implements Iterator
sourcetype Row<'conn, 'query>: Row<'conn, Self::Backend>
where
Self: 'conn
type Row<'conn, 'query>: Row<'conn, Self::Backend> where Self: 'conn
The row type used as Iterator::Item
for the iterator implementation
of LoadConnection::Cursor
Required Methods§
sourcefn load<'conn, 'query, T>(
&'conn mut self,
source: T,
) -> QueryResult<Self::Cursor<'conn, 'query>>where
T: Query + QueryFragment<Self::Backend> + QueryId + 'query,
Self::Backend: QueryMetadata<T::SqlType>,
fn load<'conn, 'query, T>(
&'conn mut self,
source: T,
) -> QueryResult<Self::Cursor<'conn, 'query>>where
T: Query + QueryFragment<Self::Backend> + QueryId + 'query,
Self::Backend: QueryMetadata<T::SqlType>,
Executes a given query and returns any requested values
This function executes a given query and returns the
query result as given by the database. Normal users
should not use this function. Use
QueryDsl::load
instead.
This function is useful for people trying to build an alternative
dsl on top of diesel. It returns an impl Iterator<Item = QueryResult<&impl Row<Self::Backend>>
.
This type can be used to iterate over all rows returned by the database.