fix(database): migrate versioned schemas before create_all

app/startup/initializers/database.py

@@ -90,7 +90,7 @@ def _validate_migration_lineage(
 
 
 def prepare_database(*, before_alembic: Callable[[], None] | None = None) -> None:
-    """在建表或迁移前完成版本校验及可选备份。"""
+    """在建表或迁移前完成版本校验、可选备份与安全的结构升级。"""
     engine = get_engine()
     alembic_cfg = _build_alembic_config(engine)
     has_existing_database, current_heads, target_heads = _migration_state(
@@ -101,6 +101,7 @@ def prepare_database(*, before_alembic: Callable[[], None] | None = None) -> Non
         has_existing_database
         and set(current_heads) != set(target_heads)
     )
+    migrate_before_create = requires_migration and bool(current_heads)
     if (
         requires_migration
         and get_runtime_setting('DB_BACKUP_ENABLE')
@@ -114,11 +115,17 @@ def prepare_database(*, before_alembic: Callable[[], None] | None = None) -> Non
         )
         build_database_governance().create_backup()
 
+    if migrate_before_create:
+        # 已标记的旧结构必须先沿 Alembic 链升级；当前元数据可能包含依赖新列的外键，
+        # 提前 create_all 会在 PostgreSQL 上因父表仍是旧结构而失败。
+        update_db(alembic_cfg)
+
     init_db()
     if before_alembic:
         # 首次初始化需要先建立用户表，再把管理员密码交给 Alembic 基础迁移消费。
         before_alembic()
-    update_db(alembic_cfg)
+    if not migrate_before_create:
+        update_db(alembic_cfg)
 
 
 def verify_database_revision() -> None:

tests/test_database_migration_startup.py

@@ -101,15 +101,40 @@ def test_prepare_database_creates_backup_before_schema_changes(monkeypatch) -> N
 
     assert calls == [
         "backup",
+        "alembic",
         "create_all",
         "before_alembic",
-        "alembic",
     ]
     assert logged_messages == [
         "数据库需要从版本 old 升级到 head，正在创建迁移前备份"
     ]
 
 
+def test_prepare_database_keeps_create_all_first_for_unversioned_database(
+        monkeypatch,
+) -> None:
+    """未标记旧库仍需先补齐基础表，再从 Alembic base 执行数据迁移。"""
+    calls: list[str] = []
+    monkeypatch.setattr(db_init, "get_engine", lambda: object())
+    monkeypatch.setattr(db_init, "_build_alembic_config", lambda _engine: object())
+    monkeypatch.setattr(
+        db_init,
+        "_migration_state",
+        lambda *_: (True, (), ("head",)),
+    )
+    monkeypatch.setattr(db_init.settings, "DB_BACKUP_ENABLE", False)
+    monkeypatch.setattr(db_init, "init_db", lambda: calls.append("create_all"))
+    monkeypatch.setattr(
+        db_init,
+        "update_db",
+        lambda _config: calls.append("alembic"),
+    )
+
+    db_init.prepare_database(before_alembic=lambda: calls.append("before_alembic"))
+
+    assert calls == ["create_all", "before_alembic", "alembic"]
+
+
 @pytest.mark.parametrize(
     ("has_existing_database", "current_heads", "backup_enabled", "upgrade_enabled"),
     (