freedakgmail
84 lines
2.5 KiB
Python
84 lines
2.5 KiB
Python
"""双时态事实仓储：写入与"按历史时点回放"查询。
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对应需求 R3 / ADR-0002：
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- 业务有效期 valid_from/valid_to（应用时间）
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- 系统记录期 system_from/system_to（事务时间）
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回放 = 给定 (as_of_valid, as_of_system) 在两条时间线上各取"包含该时点"的记录。
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"""
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from __future__ import annotations
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import datetime as dt
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import uuid
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from sqlalchemy import or_
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from sqlalchemy.orm import Session
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from app.datahub.models import BitemporalFact
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def record_fact(
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session: Session,
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entity_id: uuid.UUID,
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attr_name: str,
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attr_value: dict,
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valid_from: dt.datetime,
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valid_to: dt.datetime | None = None,
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data_version_id: uuid.UUID | None = None,
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) -> BitemporalFact:
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"""记录一条双时态事实（system_from 自动取当前事务时间）。"""
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fact = BitemporalFact(
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entity_id=entity_id,
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attr_name=attr_name,
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attr_value=attr_value,
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valid_from=valid_from,
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valid_to=valid_to,
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data_version_id=data_version_id,
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)
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session.add(fact)
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session.flush()
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return fact
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def as_of(
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session: Session,
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entity_id: uuid.UUID,
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attr_name: str,
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as_of_valid: dt.datetime,
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as_of_system: dt.datetime | None = None,
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) -> BitemporalFact | None:
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"""回放：返回在给定业务时点且按给定系统时点可见的事实。
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- 业务时间线：valid_from <= as_of_valid < valid_to(或为空表示至今)
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- 系统时间线：system_from <= as_of_system < system_to(或为空表示当前可见)
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"""
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as_of_system = as_of_system or dt.datetime.now(dt.UTC)
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q = (
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session.query(BitemporalFact)
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.filter(BitemporalFact.entity_id == entity_id)
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.filter(BitemporalFact.attr_name == attr_name)
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.filter(BitemporalFact.valid_from <= as_of_valid)
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.filter(
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or_(BitemporalFact.valid_to.is_(None), BitemporalFact.valid_to > as_of_valid)
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)
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.filter(BitemporalFact.system_from <= as_of_system)
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.filter(
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or_(
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BitemporalFact.system_to.is_(None),
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BitemporalFact.system_to > as_of_system,
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)
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)
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.order_by(BitemporalFact.system_from.desc())
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)
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return q.first()
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def close_fact(
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session: Session, fact: BitemporalFact, system_to: dt.datetime | None = None
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) -> None:
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"""逻辑关闭一条事实的系统可见期（用于更正/失效，而非物理删除）。"""
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fact.system_to = system_to or dt.datetime.now(dt.UTC)
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session.add(fact)
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session.flush()
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