Trait DbDupCursorRO

pub trait DbDupCursorRO<T>
where
    T: DupSort,
{
    // Required methods
    fn next_dup(
        &mut self,
    ) -> Result<Option<(<T as Table>::Key, <T as Table>::Value)>, DatabaseError>;
    fn next_no_dup(
        &mut self,
    ) -> Result<Option<(<T as Table>::Key, <T as Table>::Value)>, DatabaseError>;
    fn next_dup_val(
        &mut self,
    ) -> Result<Option<<T as Table>::Value>, DatabaseError>;
    fn seek_by_key_subkey(
        &mut self,
        key: <T as Table>::Key,
        subkey: <T as DupSort>::SubKey,
    ) -> Result<Option<<T as Table>::Value>, DatabaseError>;
    fn walk_dup(
        &mut self,
        key: Option<<T as Table>::Key>,
        subkey: Option<<T as DupSort>::SubKey>,
    ) -> Result<DupWalker<'_, T, Self>, DatabaseError>
       where Self: Sized;
}

A read-only cursor over the dup table T.

Required Methods

fn next_dup( &mut self, ) -> Result<Option<(<T as Table>::Key, <T as Table>::Value)>, DatabaseError>

Positions the cursor at the next KV pair of the table, returning it.

fn next_no_dup( &mut self, ) -> Result<Option<(<T as Table>::Key, <T as Table>::Value)>, DatabaseError>

Positions the cursor at the next KV pair of the table, skipping duplicates.

fn next_dup_val(&mut self) -> Result<Option<<T as Table>::Value>, DatabaseError>

Positions the cursor at the next duplicate value of the current key.

fn seek_by_key_subkey( &mut self, key: <T as Table>::Key, subkey: <T as DupSort>::SubKey, ) -> Result<Option<<T as Table>::Value>, DatabaseError>

Positions the cursor at the entry greater than or equal to the provided key/subkey pair.

Note

The position of the cursor might not correspond to the key/subkey pair if the entry does not exist.

fn walk_dup( &mut self, key: Option<<T as Table>::Key>, subkey: Option<<T as DupSort>::SubKey>, ) -> Result<DupWalker<'_, T, Self>, DatabaseError>

where Self: Sized,

Get an iterator that walks through the dup table.

The cursor will start at different points in the table depending on the values of key and subkey:

key	subkey	Equivalent starting position
None	None	DbCursorRO::first()
Some	None	DbCursorRO::seek()
None	Some	DbDupCursorRO::seek_by_key_subkey()
Some	Some	DbDupCursorRO::seek_by_key_subkey()

Implementors

impl<K: TransactionKind, T: DupSort> DbDupCursorRO<T> for Cursor<K, T>

Available on crate feature mdbx only.

impl<T> DbDupCursorRO<T> for CursorMock

where T: DupSort,