sqlmodel-fix/sqlmodel/sql/sqltypes.py
Andrew Bolster 5ea9340def
Update GUID handling to use stdlib UUID.hex instead of an int (#26)
Co-authored-by: Sebastián Ramírez <tiangolo@gmail.com>
2022-08-28 00:28:09 +02:00

62 lines
2.0 KiB
Python

import uuid
from typing import Any, Optional, cast
from sqlalchemy import types
from sqlalchemy.dialects.postgresql import UUID
from sqlalchemy.engine.interfaces import Dialect
from sqlalchemy.sql.type_api import TypeEngine
from sqlalchemy.types import CHAR, TypeDecorator
class AutoString(types.TypeDecorator): # type: ignore
impl = types.String
cache_ok = True
mysql_default_length = 255
def load_dialect_impl(self, dialect: Dialect) -> "types.TypeEngine[Any]":
impl = cast(types.String, self.impl)
if impl.length is None and dialect.name == "mysql":
return dialect.type_descriptor(types.String(self.mysql_default_length)) # type: ignore
return super().load_dialect_impl(dialect)
# Reference form SQLAlchemy docs: https://docs.sqlalchemy.org/en/14/core/custom_types.html#backend-agnostic-guid-type
# with small modifications
class GUID(TypeDecorator): # type: ignore
"""Platform-independent GUID type.
Uses PostgreSQL's UUID type, otherwise uses
CHAR(32), storing as stringified hex values.
"""
impl = CHAR
cache_ok = True
def load_dialect_impl(self, dialect: Dialect) -> TypeEngine: # type: ignore
if dialect.name == "postgresql":
return dialect.type_descriptor(UUID()) # type: ignore
else:
return dialect.type_descriptor(CHAR(32)) # type: ignore
def process_bind_param(self, value: Any, dialect: Dialect) -> Optional[str]:
if value is None:
return value
elif dialect.name == "postgresql":
return str(value)
else:
if not isinstance(value, uuid.UUID):
return uuid.UUID(value).hex
else:
# hexstring
return value.hex
def process_result_value(self, value: Any, dialect: Dialect) -> Optional[uuid.UUID]:
if value is None:
return value
else:
if not isinstance(value, uuid.UUID):
value = uuid.UUID(value)
return cast(uuid.UUID, value)