Class SchemaField (3.27.0)

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,
)

Describe a single field within a table schema.

Properties

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'.

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".

scale

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

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`	`Mapping[str, str]` 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.