Struct datafusion_expr::expr::Placeholder

pub struct Placeholder {
    pub id: String,
    pub data_type: Option<DataType>,
}

Placeholder, representing bind parameter values such as $1 or $name.

The type of these parameters is inferred using Expr::infer_placeholder_types or can be specified directly using PREPARE statements.

Fields

id: String

The identifier of the parameter, including the leading $ (e.g, "$1" or "$foo")

data_type: Option<DataType>

The type the parameter will be filled in with

Implementations

impl Placeholder

pub fn new(id: String, data_type: Option<DataType>) -> Self

Create a new Placeholder expression

Trait Implementations

impl Clone for Placeholder

fn clone(&self) -> Placeholder

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Placeholder

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

Formats the value using the given formatter.

impl Hash for Placeholder

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Placeholder

fn eq(&self, other: &Placeholder) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for Placeholder

impl StructuralPartialEq for Placeholder