Struct NowFunc 

pub struct NowFunc { /* private fields */ }

Available on crate feature datetime_expressions only.

Implementations

impl NowFunc

pub fn new() -> Self

Trait Implementations

impl Debug for NowFunc

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

Formats the value using the given formatter.

impl Default for NowFunc

fn default() -> Self

Returns the “default value” for a type.

impl Hash for NowFunc

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 NowFunc

fn eq(&self, other: &NowFunc) -> 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 ScalarUDFImpl for NowFunc

Create an implementation of now() that always returns the specified timestamp.

The semantics of now() require it to return the same value wherever it appears within a single statement. This value is chosen during planning time.

fn as_any(&self) -> &dyn Any

Returns this object as an Any trait object

fn name(&self) -> &str

Returns this function’s name

fn signature(&self) -> &Signature

Returns a Signature describing the argument types for which this function has an implementation, and the function’s Volatility.

fn return_field_from_args(&self, _args: ReturnFieldArgs<'_>) -> Result<FieldRef>

What type will be returned by this function, given the arguments?

fn return_type(&self, _arg_types: &[DataType]) -> Result<DataType>

DataType returned by this function, given the types of the arguments.

fn invoke_with_args(&self, _args: ScalarFunctionArgs) -> Result<ColumnarValue>

Invoke the function returning the appropriate result.

fn simplify( &self, _args: Vec<Expr>, info: &dyn SimplifyInfo, ) -> Result<ExprSimplifyResult>

Optionally apply per-UDF simplification / rewrite rules.

fn aliases(&self) -> &[String]

Returns any aliases (alternate names) for this function.

fn documentation(&self) -> Option<&Documentation>

Returns the documentation for this Scalar UDF.

fn display_name(&self, args: &[Expr]) -> Result<String, DataFusionError>

👎Deprecated since 50.0.0: This method is unused and will be removed in a future release

Returns the user-defined display name of function, given the arguments

fn schema_name(&self, args: &[Expr]) -> Result<String, DataFusionError>

Returns the name of the column this expression would create

fn is_nullable(&self, _args: &[Expr], _schema: &dyn ExprSchema) -> bool

👎Deprecated since 45.0.0: Use return_field_from_args instead. if you use is_nullable that returns non-nullable with return_type, you would need to switch to return_field_from_args, you might have error

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.

fn evaluate_bounds( &self, _input: &[&Interval], ) -> Result<Interval, DataFusionError>

Computes the output Interval for a ScalarUDFImpl, given the input intervals.

fn propagate_constraints( &self, _interval: &Interval, _inputs: &[&Interval], ) -> Result<Option<Vec<Interval>>, DataFusionError>

Updates bounds for child expressions, given a known Intervals for this function.

fn output_ordering( &self, inputs: &[ExprProperties], ) -> Result<SortProperties, DataFusionError>

Calculates the SortProperties of this function based on its children’s properties.

fn preserves_lex_ordering( &self, _inputs: &[ExprProperties], ) -> Result<bool, DataFusionError>

Returns true if the function preserves lexicographical ordering based on the input ordering.

fn coerce_types( &self, _arg_types: &[DataType], ) -> Result<Vec<DataType>, DataFusionError>

Coerce arguments of a function call to types that the function can evaluate.

impl Eq for NowFunc

impl StructuralPartialEq for NowFunc