Struct NowFunc

pub struct NowFunc { /* private fields */ }

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 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 the function’s Signature for information about what input types are accepted and the function’s Volatility.

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

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

fn invoke(&self, _args: &[ColumnarValue]) -> Result<ColumnarValue>

👎Deprecated since 42.1.0: Use invoke_batch instead

Invoke the function on args, returning the appropriate result

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

Optionally apply per-UDF simplification / rewrite rules.

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

Returns the documentation for this Scalar UDF.

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

Returns any aliases (alternate names) for this function.

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

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

Returns the user-defined display name of the UDF given the arguments

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

Returns the name of the column this expression would create

fn return_type_from_exprs( &self, _args: &[Expr], _schema: &dyn ExprSchema, arg_types: &[DataType], ) -> Result<DataType, DataFusionError>

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

fn invoke_batch( &self, args: &[ColumnarValue], number_rows: usize, ) -> Result<ColumnarValue, DataFusionError>

Invoke the function with args and the number of rows, returning the appropriate result.

fn invoke_no_args( &self, _number_rows: usize, ) -> Result<ColumnarValue, DataFusionError>

👎Deprecated since 42.1.0: Use invoke_batch instead

Invoke the function without args, instead the number of rows are provided, returning the appropriate result.

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 Setting this to true prevents certain optimizations such as common subexpression elimination

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 interval for this function. This is used to propagate constraints down through an expression tree.

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

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

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

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

fn equals(&self, other: &dyn ScalarUDFImpl) -> bool

Return true if this scalar UDF is equal to the other.

fn hash_value(&self) -> u64

Returns a hash value for this scalar UDF.