Struct CoalesceFunc

pub struct CoalesceFunc { /* private fields */ }

Implementations

impl CoalesceFunc

pub fn new() -> CoalesceFunc

Trait Implementations

impl Debug for CoalesceFunc

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

Formats the value using the given formatter.

impl Default for CoalesceFunc

fn default() -> CoalesceFunc

Returns the “default value” for a type.

impl ScalarUDFImpl for CoalesceFunc

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

coalesce evaluates to the first value which is not NULL

fn as_any(&self) -> &(dyn Any + 'static)

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, DataFusionError>

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

fn return_field_from_args( &self, args: ReturnFieldArgs<'_>, ) -> Result<Arc<Field>, DataFusionError>

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

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

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

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

Returns the documentation for this Scalar UDF.

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

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 aliases(&self) -> &[String]

Returns any aliases (alternate names) for this function.

fn simplify( &self, args: Vec<Expr>, _info: &dyn SimplifyInfo, ) -> Result<ExprSimplifyResult, DataFusionError>

Optionally apply per-UDF simplification / rewrite rules.

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 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.