Python 随着数据集变大，CPU也会随之增加。uuid字符串格式因语言而异，增加了所需的翻译。有人更容易滥用该列，因为您可以在其中放入任何东西，而不是UUID。这应该足够开始了。为了性能问题，不应该将字符串用作uuid的列。更推荐使用二进制（16）。sqlite是否

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随着数据集变大，CPU也会随之增加。uuid字符串格式因语言而异，增加了所需的翻译。有人更容易滥用该列，因为您可以在其中放入任何东西，而不是UUID。这应该足够开始了。为了性能问题，不应该将字符串用作uuid的列。更推荐使用二进制（16）。sqlite是否符合“非常奇怪的数据库”的条件p对于使用PostgreSQL数据库的开发人员来说，这应该是唯一可以接受的答案。

import sqlalchemy.types as types

class UUID(types.TypeEngine):
    def get_col_spec(self):
        return "uuid"

    def bind_processor(self, dialect):
        def process(value):
            return value
        return process

    def result_processor(self, dialect):
        def process(value):
            return value
        return process

table = Table('foo', meta,
    Column('id', UUID(), primary_key=True),
)

from sqlalchemy import types
from sqlalchemy.dialects.mysql.base import MSBinary
from sqlalchemy.schema import Column
import uuid


class UUID(types.TypeDecorator):
    impl = MSBinary
    def __init__(self):
        self.impl.length = 16
        types.TypeDecorator.__init__(self,length=self.impl.length)

    def process_bind_param(self,value,dialect=None):
        if value and isinstance(value,uuid.UUID):
            return value.bytes
        elif value and not isinstance(value,uuid.UUID):
            raise ValueError,'value %s is not a valid uuid.UUID' % value
        else:
            return None

    def process_result_value(self,value,dialect=None):
        if value:
            return uuid.UUID(bytes=value)
        else:
            return None

    def is_mutable(self):
        return False


id_column_name = "id"

def id_column():
    import uuid
    return Column(id_column_name,UUID(),primary_key=True,default=uuid.uuid4)

# Usage
my_table = Table('test',
         metadata,
         id_column(),
         Column('parent_id',
            UUID(),
            ForeignKey(table_parent.c.id)))

class UUID(types.TypeDecorator):
    impl = types.LargeBinary

    def __init__(self):
        self.impl.length = 16
        types.TypeDecorator.__init__(self, length=self.impl.length)

    def process_bind_param(self, value, dialect=None):
        if value and isinstance(value, uuid.UUID):
            return value.bytes
        elif value and isinstance(value, basestring):
            return uuid.UUID(value).bytes
        elif value:
            raise ValueError('value %s is not a valid uuid.UUId' % value)
        else:
            return None

    def process_result_value(self, value, dialect=None):
        if value:
            return uuid.UUID(bytes=value)
        else:
            return None

    def is_mutable(self):
        return False

import uuid

from sqlalchemy.types import TypeDecorator, BINARY
from sqlalchemy.dialects.postgresql import UUID as psqlUUID

class UUID(TypeDecorator):
    """Platform-independent GUID type.

    Uses Postgresql's UUID type, otherwise uses
    BINARY(16), to store UUID.

    """
    impl = BINARY

    def load_dialect_impl(self, dialect):
        if dialect.name == 'postgresql':
            return dialect.type_descriptor(psqlUUID())
        else:
            return dialect.type_descriptor(BINARY(16))

    def process_bind_param(self, value, dialect):
        if value is None:
            return value
        else:
            if not isinstance(value, uuid.UUID):
                if isinstance(value, bytes):
                    value = uuid.UUID(bytes=value)
                elif isinstance(value, int):
                    value = uuid.UUID(int=value)
                elif isinstance(value, str):
                    value = uuid.UUID(value)
        if dialect.name == 'postgresql':
            return str(value)
        else:
            return value.bytes

    def process_result_value(self, value, dialect):
        if value is None:
            return value
        if dialect.name == 'postgresql':
            return uuid.UUID(value)
        else:
            return uuid.UUID(bytes=value)

def generate_uuid():
    return str(uuid.uuid4())

class MyTable(Base):
    __tablename__ = 'my_table'

    uuid = Column(String, name="uuid", primary_key=True, default=generate_uuid)

from sqlalchemy.dialects.postgresql import UUID
from flask_sqlalchemy import SQLAlchemy
import uuid

db = SQLAlchemy()

class Foo(db.Model):
    id = db.Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)