gravitino.dto.rel.expressions.field_reference_dto.FieldReferenceDTO¶

class gravitino.dto.rel.expressions.field_reference_dto.FieldReferenceDTO(field_name: List[str])¶

Bases: NamedReference, FunctionArg

Data transfer object representing a field reference.

__init__(field_name: List[str])¶

Methods

`__init__`(field_name)
`arg_type`()	Arguments type of the function.
`builder`()	The builder for creating a new instance of FieldReferenceDTO.
`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.
`validate`(columns)	Validates the function argument.

Attributes

`EMPTY_ARGS`
`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.

class ArgType(value)¶

Bases: str, Enum

The type of the argument.

The supported types are:

LITERAL: A literal argument.
FIELD: A field argument.
FUNCTION: A function argument.
UNPARSED: An unparsed argument.

class Builder¶

Bases: object

Builder for FieldRererenceDTO

build() → FieldReferenceDTO¶

Build the field reference.

Returns:: FieldReferenceDTO: The field reference.

with_column_name(column_name: str) → Builder¶

Set the column name for the field reference.

Args:: column_name (str): The column name.
Returns:: FieldReferenceDTO.Builder: The builder.

with_field_name(field_name: List[str]) → Builder¶

Set the field name for the field reference.

Args:: field_name (List[str]): The field name.
Returns:: FieldReferenceDTO.Builder: The builder.

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.

arg_type() → ArgType¶

Arguments type of the function.

Returns:: ArgType: The type of this argument.

static builder() → Builder¶

The builder for creating a new instance of FieldReferenceDTO.

Returns:: Builder: The builder for creating a new instance of FieldReferenceDTO.

children() → list[gravitino.api.expressions.expression.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[gravitino.api.expressions.named_reference.NamedReference]¶: Named references reference themselves.

validate(columns: List[ColumnDTO]) → None¶

Validates the function argument.

Args:: columns (List[ColumnDTO]): The columns of the table.
Raises:: IllegalArgumentException: If the function argument is invalid.