Struct ColumnInfo 

pub struct ColumnInfo {
    pub name: String,
    pub data_type: DataType,
    pub nullable: bool,
    pub position: usize,
    pub table_name: Option<String>,
    pub cql_type: Option<CqlType>,
}

Information about a column in the result set

Fields

name: String

Column name

data_type: DataType

Column data type (flat, kept for backward compatibility)

nullable: bool

Whether column can be null

position: usize

Column position in result set

table_name: Option<String>

Original table name (for joined queries)

cql_type: Option<CqlType>

Full schema-sourced CQL type (populated when a schema is available).

This field expresses element types for collections (list<int>, map<text, bigint>), and carries variants absent from the flat DataType enum (date, time, decimal, varint, counter, duration, inet). Downstream writers MUST use this over data_type when it is Some — the no-heuristics mandate (Issue #28) requires authoritative-schema metadata rather than runtime inference.

Implementations

impl ColumnInfo

pub fn new( name: String, data_type: DataType, nullable: bool, position: usize, ) -> Self

Create new column info

pub fn with_table_name(self, table_name: String) -> Self

Set table name

pub fn with_cql_type(self, cql_type: CqlType) -> Self

Attach a schema-sourced CqlType to this column.

The data_type field is left unchanged so existing consumers remain unaffected; downstream writers that need full type fidelity (e.g. the Parquet/Arrow writer) should prefer cql_type when it is Some.

pub fn to_json(&self) -> Value

Convert to JSON representation

The data_type and all pre-existing keys are preserved unchanged for backward compatibility. The new cql_type key is only emitted when the field is Some (it is marked skip_serializing_if in the struct derive, but we also reflect it here for the hand-rolled JSON path).

Trait Implementations

impl Clone for ColumnInfo

fn clone(&self) -> ColumnInfo

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ColumnInfo

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for ColumnInfo

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for ColumnInfo

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.