Struct NOW_EXPR

struct NOW_EXPR {
    __private_field: (),
}

The [Expr] to call UDF function now().

Fields

__private_field: ()

Methods from Deref<Target = Expr>

pub fn display_name(&self) -> Result<String, DataFusionError>

Returns the name of this expression as it should appear in a schema. This name will not include any CAST expressions.

pub fn canonical_name(&self) -> String

Returns a full and complete string representation of this expression.

pub fn variant_name(&self) -> &str

Return String representation of the variant represented by self Useful for non-rust based bindings

pub fn name_for_alias(&self) -> Result<String, DataFusionError>

Return the name to use for the specific Expr, recursing into Expr::Sort as appropriate

pub fn try_into_col(&self) -> Result<Column, DataFusionError>

👎Deprecated since 39.0.0: use try_as_col instead

pub fn try_as_col(&self) -> Option<&Column>

Return a reference to the inner Column if any

returns None if the expression is not a Column

Example

use datafusion_expr::{col, Expr};
let expr = col("foo");
assert_eq!(expr.try_as_col(), Some(&Column::from("foo")));

let expr = col("foo").alias("bar");
assert_eq!(expr.try_as_col(), None);

pub fn to_columns(&self) -> Result<HashSet<Column>, DataFusionError>

Return all referenced columns of this expression.

pub fn contains_outer(&self) -> bool

Return true when the expression contains out reference(correlated) expressions.

pub fn is_volatile(&self) -> Result<bool, DataFusionError>

Returns true if the expression is volatile, i.e. whether it can return different results when evaluated multiple times with the same input.

pub fn short_circuits(&self) -> bool

Returns true if some of this exprs subexpressions may not be evaluated and thus any side effects (like divide by zero) may not be encountered

Trait Implementations

impl Deref for NOW_EXPR

type Target = Expr

The resulting type after dereferencing.

fn deref(&self) -> &Expr

Dereferences the value.

impl LazyStatic for NOW_EXPR