Struct ColumnMap 

pub struct ColumnMap { /* private fields */ }

Column for Map(K, V) type, stored internally as Array(Tuple(K, V)).

Implementations

impl ColumnMap

pub fn new(type_: Type) -> Self

Create a new empty map column for the given Map type.

Panics

Panics if type_ is not Type::Map.

pub fn from_array(type_: Type, data: ColumnRef) -> Self

Create from existing array data

pub fn data<T: Column + 'static>(&self) -> &T

Get a reference to the data column as a specific type

Example

let col: ColumnMap = /* ... */;
let data: &ColumnArray = col.data();

pub fn data_mut<T: Column + 'static>(&mut self) -> &mut T

Get mutable reference to the data column as a specific type

Example

let mut col: ColumnMap = /* ... */;
let data_mut: &mut ColumnArray = col.data_mut();

pub fn data_ref(&self) -> ColumnRef

Get the data column as a ColumnRef (Arc<dyn Column>)

pub fn as_array(&self) -> Option<&ColumnArray>

Get the underlying array column as ColumnArray if possible

pub fn at(&self, index: usize) -> Result<ColumnRef>

Get map at index as a column reference The returned column is a Tuple(K, V) array

pub fn len(&self) -> usize

Returns the number of map entries (rows) in this column.

pub fn is_empty(&self) -> bool

Returns true if the column contains no entries.

Trait Implementations

impl Clone for ColumnMap

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Column for ColumnMap

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

Load column data from byte buffer

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.

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