gravitino.api.expressions.named_reference.FieldReference

class gravitino.api.expressions.named_reference.FieldReference(field_names: list[str])

Bases: NamedReference

A NamedReference that references a field or column.

__init__(field_names: list[str])

Methods

__init__(field_names)
children()	Named references do not have children.
field(field_name)	Returns a FieldReference for the given field name(s).
field_from_column(column_name)	Returns a FieldReference for the given column name.
field_name()	Returns the referenced field name as a list of string parts.
references()	Named references reference themselves.

Attributes

EMPTY_EXPRESSION	EMPTY_EXPRESSION is only used as an input when the default children method builds the result.
EMPTY_NAMED_REFERENCE	EMPTY_NAMED_REFERENCE is only used as an input when the default references method builds the result array to avoid repeatedly allocating an empty array.

EMPTY_EXPRESSION: List[Expression] = []

EMPTY_EXPRESSION is only used as an input when the default children method builds the result.

EMPTY_NAMED_REFERENCE: List[NamedReference] = []

EMPTY_NAMED_REFERENCE is only used as an input when the default references method builds the result array to avoid repeatedly allocating an empty array.

children() → list[Expression]

Named references do not have children.

static field(field_name: list[str]) → FieldReference

Returns a FieldReference for the given field name(s). The array of field name(s) is used to reference nested fields. For example, if we have a struct column named “student” with a data type of StructType{“name”: StringType, “age”: IntegerType}, we can reference the field “name” by calling field(“student”, “name”).

@param field_name the field name(s) @return a FieldReference for the given field name(s)

static field_from_column(column_name: str) → FieldReference

Returns a FieldReference for the given column name.

field_name() → list[str]

Returns the referenced field name as a list of string parts. Must be implemented by subclasses.

references() → list[NamedReference]

Named references reference themselves.