Class SchemaField (3.47.0) 

SchemaField(
    name: str,
    field_type: str,
    mode: str = "NULLABLE",
    default_value_expression: typing.Optional[str] = None,
    description: typing.Union[
        str, google.cloud.bigquery.schema._DefaultSentinel
    ] = _DefaultSentinel.DEFAULT_VALUE,
    fields: typing.Iterable[google.cloud.bigquery.schema.SchemaField] = (),
    policy_tags: typing.Union[
        google.cloud.bigquery.schema.PolicyTagList,
        None,
        google.cloud.bigquery.schema._DefaultSentinel,
    ] = _DefaultSentinel.DEFAULT_VALUE,
    precision: typing.Union[
        int, google.cloud.bigquery.schema._DefaultSentinel
    ] = _DefaultSentinel.DEFAULT_VALUE,
    scale: typing.Union[
        int, google.cloud.bigquery.schema._DefaultSentinel
    ] = _DefaultSentinel.DEFAULT_VALUE,
    max_length: typing.Union[
        int, google.cloud.bigquery.schema._DefaultSentinel
    ] = _DefaultSentinel.DEFAULT_VALUE,
    range_element_type: typing.Optional[
        typing.Union[google.cloud.bigquery.schema.FieldElementType, str]
    ] = None,
    rounding_mode: typing.Optional[
        typing.Union[google.cloud.bigquery.enums.RoundingMode, str]
    ] = None,
    foreign_type_definition: typing.Optional[str] = None,
    timestamp_precision: typing.Optional[
        google.cloud.bigquery.enums.TimestampPrecision
    ] = None,
    *,
    data_policies: typing.Union[
        typing.Iterable[google.cloud.bigquery.schema.DataPolicy],
        None,
        google.cloud.bigquery.schema._DefaultSentinel,
    ] = _DefaultSentinel.DEFAULT_VALUE
)

Describe a single field within a table schema.

Properties

data_policies

Optional[Tuple[google.cloud.bigquery.schema.DataPolicy, ...]]: Data policies for this field.

Returns objects from the REST dataPolicies field, or None if unset. An explicitly empty list is returned as an empty tuple. Each object preserves all properties from its API representation.

See: https://cloud.google.com/bigquery/docs/reference/rest/v2/tables#TableFieldSchema

default_value_expression

Optional[str] default value of a field, using an SQL expression

description

Optional[str]: description for the field.

field_type

str: The type of the field.

See: https://cloud.google.com/bigquery/docs/reference/rest/v2/tables#TableFieldSchema.FIELDS.type

fields

Optional[tuple]: Subfields contained in this field.

Must be empty unset if field_type is not 'RECORD'.

foreign_type_definition

Definition of the foreign data type.

Only valid for top-level schema fields (not nested fields). If the type is FOREIGN, this field is required.

is_nullable

bool: whether 'mode' is 'nullable'.

max_length

Optional[int]: Maximum length for the STRING or BYTES field.

mode

Optional[str]: The mode of the field.

See: https://cloud.google.com/bigquery/docs/reference/rest/v2/tables#TableFieldSchema.FIELDS.mode

name

str: The name of the field.

policy_tags

Optional[google.cloud.bigquery.schema.PolicyTagList]: Policy tag list definition for this field.

precision

Optional[int]: Precision (number of digits) for the NUMERIC field.

range_element_type

Optional[FieldElementType]: The subtype of the RANGE, if the type of this field is RANGE.

Must be set when type is "RANGE". Must be one of "DATE", "DATETIME" or "TIMESTAMP".

rounding_mode

Enum that specifies the rounding mode to be used when storing values of NUMERIC and BIGNUMERIC type.

scale

Optional[int]: Scale (digits after decimal) for the NUMERIC field.

timestamp_precision

Precision (maximum number of total digits in base 10) for seconds of TIMESTAMP type.

Returns
Type Description
enums.TimestampPrecision value of TimestampPrecision.

Methods

from_api_repr

from_api_repr(api_repr: dict) -> google.cloud.bigquery.schema.SchemaField

Return a SchemaField object deserialized from a dictionary.

Parameter
Name Description
api_repr dict

The serialized representation of the SchemaField, such as what is output by to_api_repr.
Returns
Type Description
google.cloud.bigquery.schema.SchemaField The SchemaField object.

to_api_repr

to_api_repr() -> dict

Return a dictionary representing this schema field.

Returns
Type Description
Dict A dictionary representing the SchemaField in a serialized form.

to_standard_sql

to_standard_sql() -> google.cloud.bigquery.standard_sql.StandardSqlField

Return the field as the standard SQL field representation object.