Typing & Schema Aliases¶

from sqlspec.typing import (
    UNSET,
    ArrowReturnFormat,
    ConnectionT,
    DataclassProtocol,
    DictLike,
    Empty,
    EmptyType,
    PoolT,
    SchemaT,
    StatementParameters,
    SupportedSchemaModel,
    UnsetType,
    get_type_adapter,
)

Public type variables, schema model union aliases, Apache Arrow return format literals, and sentinel types exported by sqlspec.typing. See Schema Mapping for usage examples.

Core Type Variables & Aliases¶

ConnectionT ¶

ConnectionT = TypeVar('ConnectionT')

Type variable for connection types.

:class:~sqlspec.typing.ConnectionT

PoolT ¶

PoolT = TypeVar('PoolT')

Type variable for pool types.

:class:~sqlspec.typing.PoolT

SchemaT ¶

SchemaT = TypeVar('SchemaT', default=dict[str, Any])

Type variable for schema types (models, TypedDict, dataclasses, etc.).

Unbounded TypeVar for use with schema_type parameter in driver methods. Supports all schema types including TypedDict which cannot be bounded to a class hierarchy.

SupportedSchemaModel ¶

SupportedSchemaModel = (
    DictLike
    | StructStub
    | BaseModelStub
    | DataclassProtocol
    | AttrsInstanceStub
    | Mapping[str, Any]
)

Type alias for pydantic or msgspec models.

:class:msgspec.Struct | :class:pydantic.BaseModel | :class:DataclassProtocol | :class:AttrsInstance

StatementParameters ¶

StatementParameters = (
    "dict[str, object] | list[object] | tuple[object, ...] | object | None"
)

Type alias for statement parameters.

Represents

:type:dict[str, object]
:type:list[object]
:type:tuple[object, ...]
:type:object
:type:None

ArrowReturnFormat ¶

ArrowReturnFormat = Literal['table', 'reader', 'batch', 'batches']

Type alias for Apache Arrow return format options.

Represents

:literal:"table" - Return PyArrow Table
:literal:"reader" - Return PyArrow RecordBatchReader
:literal:"batch" - Return single PyArrow RecordBatch
:literal:"batches" - Return list of PyArrow RecordBatches

Schema Protocols & Adapter Helpers¶

DictLike ¶

Bases: Protocol

A protocol for objects that behave like a dictionary for reading.

DataclassProtocol ¶

Bases: Protocol

Protocol for instance checking dataclasses.

get_type_adapter ¶

get_type_adapter(f)

Caches and returns a pydantic type adapter.

Parameters:

Name	Type	Description	Default
`f`	`type[T]`	Type to create a type adapter for.	required

Returns:

Type	Description
`Any`	class:`pydantic.TypeAdapter`[:class:`typing.TypeVar`[T]]

Sentinel Types & Optional Dependency Flags¶

UnsetType ¶

UnsetType = _RealUnsetType

EmptyEnum ¶

Bases: Enum

A sentinel enum used as placeholder.

EMPTY ¶

EMPTY = 0

Constant	Description
`UNSET`	Singleton sentinel indicating an omitted optional parameter.
`Empty`	Legacy sentinel alias for omitted parameters.
`MSGSPEC_INSTALLED`	`True` when `msgspec` is available at runtime.
`PYDANTIC_INSTALLED`	`True` when `pydantic` is available at runtime.
`ATTRS_INSTALLED`	`True` when `attrs` is available at runtime.
`CATTRS_INSTALLED`	`True` when `cattrs` is available at runtime.
`PYARROW_INSTALLED`	`True` when `pyarrow` is available at runtime.
`POLARS_INSTALLED`	`True` when `polars` is available at runtime.
`PANDAS_INSTALLED`	`True` when `pandas` is available at runtime.
`NUMPY_INSTALLED`	`True` when `numpy` is available at runtime.
`LITESTAR_INSTALLED`	`True` when `litestar` is available at runtime.
`OPENTELEMETRY_INSTALLED`	`True` when `opentelemetry-api` is available at runtime.
`PROMETHEUS_INSTALLED`	`True` when `prometheus-client` is available at runtime.
`FSSPEC_INSTALLED`	`True` when `fsspec` is available at runtime.
`OBSTORE_INSTALLED`	`True` when `obstore` is available at runtime.