Struct ColumnNothing 

pub struct ColumnNothing { /* private fields */ }

Column for Nothing/Void type. Tracks row count without storing data.

Implementations

impl ColumnNothing

pub fn new(type_: Type) -> Self

Create a new empty Nothing column.

pub fn with_size(self, size: usize) -> Self

Set the initial size (number of nothing/null entries).

pub fn append(&mut self)

Append a NULL/nothing value (just increments size)

pub fn at(&self, _index: usize) -> Option<()>

Get value at index (always returns None)

pub fn len(&self) -> usize

Returns the number of entries in this column.

pub fn is_empty(&self) -> bool

Returns true if the column contains no entries.

Trait Implementations

impl Column for ColumnNothing

fn column_type(&self) -> &Type

Get the type of this column

fn size(&self) -> usize

Get the number of rows in this column

fn clear(&mut self)

Clear all data from the column

fn reserve(&mut self, _new_cap: usize)

Reserve capacity for at least new_cap elements

fn append_column(&mut self, other: ColumnRef) -> Result<()>

Append another column’s data to this column

fn load_from_buffer(&mut self, buffer: &mut &[u8], rows: usize) -> Result<()>

Load column data from byte buffer

fn save_to_buffer(&self, _buffer: &mut BytesMut) -> Result<()>

Save column data to byte buffer

fn clone_empty(&self) -> ColumnRef

Create an empty clone of this column (same type, no data)

fn slice(&self, _begin: usize, len: usize) -> Result<ColumnRef>

Create a slice of this column

fn as_any(&self) -> &dyn Any

Downcast to a concrete column type

fn as_any_mut(&mut self) -> &mut dyn Any

Downcast to a mutable concrete column type

fn load_prefix(&mut self, _buffer: &mut &[u8], _rows: usize) -> Result<()>

Load column prefix from byte buffer (for types that need prefix data) Default implementation is a no-op. Override for types like LowCardinality. This matches C++ clickhouse-cpp’s LoadPrefix pattern.

fn save_prefix(&self, _buffer: &mut BytesMut) -> Result<()>

Save column prefix to byte buffer (for types that need prefix data) Default implementation is a no-op. Override for types like LowCardinality, Array with special nested types. This matches C++ clickhouse-cpp’s SavePrefix pattern.