Struct Expression 

pub struct Expression { /* private fields */ }

RAII wrapper for a duckdb_expression.

Automatically destroyed when dropped.

Implementations

impl Expression

pub const unsafe fn from_raw(raw: duckdb_expression) -> Self

Wraps a raw duckdb_expression handle, taking ownership.

Safety

raw must be a valid duckdb_expression returned by a DuckDB API call (e.g. duckdb_scalar_function_bind_get_argument). The caller must not destroy the handle after this call.

pub const fn as_raw(&self) -> duckdb_expression

Returns the raw handle without consuming the Expression.

pub const fn is_null(&self) -> bool

Returns true if the underlying handle is null.

pub fn return_type(&self) -> Option<LogicalType>

Returns the static return type of this expression, or None if the handle is null.

pub fn is_foldable(&self) -> bool

Returns true if this expression is foldable — i.e. it is constant and can be evaluated to a single Value via fold without per-row input.

pub fn fold(&self, context: &ClientContext) -> Result<Value, ErrorData>

Folds this (constant) expression into a single Value.

Only valid when is_foldable returns true.

Errors

Returns the structured ErrorData if folding fails (for example because the expression is not constant).

Trait Implementations

impl Drop for Expression

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.