Query

Defines a query parameter for a FastAPI path operation, allowing for the configuration of metadata, validation constraints, and OpenAPI schema documentation. It supports various validations such as string length, numeric ranges, and regex patterns while providing options for aliases and deprecation status.

def Query(
    default: Any = Undefined,
    default_factory: Callable[[], Any] | None = _Unset,
    alias: str | None = null,
    alias_priority: int | None = _Unset,
    validation_alias: str | AliasPath | AliasChoices | None = null,
    serialization_alias: str | None = null,
    title: str | None = null,
    description: str | None = null,
    gt: float | None = null,
    ge: float | None = null,
    lt: float | None = null,
    le: float | None = null,
    min_length: int | None = null,
    max_length: int | None = null,
    pattern: str | None = null,
    regex: str | None = null,
    discriminator: str | None = null,
    strict: bool | None = _Unset,
    multiple_of: float | None = _Unset,
    allow_inf_nan: bool | None = _Unset,
    max_digits: int | None = _Unset,
    decimal_places: int | None = _Unset,
    examples: list[Any] | None = null,
    example: Any | None = _Unset,
    openapi_examples: dict[str, Example] | None = null,
    deprecated: deprecated | str | bool | None = null,
    include_in_schema: bool = true,
    json_schema_extra: dict[str, Any] | None = null
) - > Any

Declares a query parameter for an API endpoint, providing metadata and validation rules for incoming request data.

Parameters

Name	Type	Description
default	`Any` = Undefined	The default value to use if the query parameter is not provided in the request.
default_factory	`Callable[[], Any]	None` = _Unset
alias	`str	None` = null
alias_priority	`int	None` = _Unset
validation_alias	`str	AliasPath
serialization_alias	`str	None` = null
title	`str	None` = null
description	`str	None` = null
gt	`float	None` = null
ge	`float	None` = null
lt	`float	None` = null
le	`float	None` = null
min_length	`int	None` = null
max_length	`int	None` = null
pattern	`str	None` = null
regex	`str	None` = null
discriminator	`str	None` = null
strict	`bool	None` = _Unset
multiple_of	`float	None` = _Unset
allow_inf_nan	`bool	None` = _Unset
max_digits	`int	None` = _Unset
decimal_places	`int	None` = _Unset
examples	`list[Any]	None` = null
example	`Any	None` = _Unset
openapi_examples	`dict[str, Example]	None` = null
deprecated	`deprecated	str
include_in_schema	`bool` = true	Controls whether this parameter is visible in the generated OpenAPI documentation.
json_schema_extra	`dict[str, Any]	None` = null

Returns

Type	Description
`Any`	A parameter metadata object used by FastAPI to handle query string extraction and validation.

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Returns​

Parameters

Returns