feat: add PostgreSQL database backend support

Add multi-database support allowing selection between SQL Server and
PostgreSQL via database.active config. Changes include dialect-aware
SQL generation, cross-database timestamp functions, PostgreSQL connection
URL builder, and psycopg dependency.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.gitignore

@@ -11,3 +11,5 @@ build/
 # Config with secrets
 config/settings.yaml
 config/settings.local.yaml
+
+.runtime

README.md

@@ -22,14 +22,24 @@ Edit `config/settings.yaml` to configure your environment:
 
 ```yaml
 database:
+  active: sql_server  # sql_server or postgresql
   sql_server:
     host: your-host
     port: 1433
     database: your-database
     username: your-username
     password: your-password
+  postgresql:
+    host: your-postgres-host
+    port: 5432
+    database: your-database
+    username: your-username
+    password: your-password
 ```
 
+Set `database.active` to choose the database backend. Both backends expect the
+same database name, schemas, and table structure.
+
 ### Local Overrides
 
 For local development, create `config/settings.local.yaml` to override specific values without committing them.

app/models/finished_goods.py

@@ -20,7 +20,10 @@ class FinishedGoodsLocation(Base):
     zongpai_no: Mapped[str] = mapped_column(String(64), nullable=False)
     location_code: Mapped[str] = mapped_column(String(64), nullable=False)
     created_at: Mapped[datetime] = mapped_column(
-        DateTime, nullable=False, server_default=func.getdate()
+        DateTime,
+        nullable=False,
+        default=func.current_timestamp(),
+        server_default=func.current_timestamp(),
     )
 
 
@@ -36,7 +39,10 @@ class FinishedGoodsBox(Base):
     paichan_no: Mapped[str] = mapped_column(String(64), nullable=False)
     box_no: Mapped[int] = mapped_column(nullable=False)
     created_at: Mapped[datetime] = mapped_column(
-        DateTime, nullable=False, server_default=func.getdate()
+        DateTime,
+        nullable=False,
+        default=func.current_timestamp(),
+        server_default=func.current_timestamp(),
     )
 
 
@@ -53,5 +59,8 @@ class FinishedGoodsBoxItem(Base):
     zongpai_no: Mapped[str] = mapped_column(String(64), nullable=False)
     quantity: Mapped[float | None] = mapped_column(Numeric(18, 3), nullable=True)
     created_at: Mapped[datetime] = mapped_column(
-        DateTime, nullable=False, server_default=func.getdate()
+        DateTime,
+        nullable=False,
+        default=func.current_timestamp(),
+        server_default=func.current_timestamp(),
     )

app/services/box_service.py

@@ -25,11 +25,7 @@ class DuplicateBoxItemError(Exception):
 
 def query_erp_info(db: Session, zongpai_no: str) -> dict:
     """从 ERP 视图查询总排号对应的排产号和数量。"""
-    sql = text(
+    sql = text(_erp_info_sql(db))
-        "SELECT TOP 1 [总排号], [排产号], [数量] "
-        "FROM [ERPAuto].[vw_productionContractData] "
-        "WHERE [总排号] = :zongpai_no"
-    )
     row = db.execute(sql, {"zongpai_no": zongpai_no}).fetchone()
     if not row:
         raise ZongpaiNotFoundError()
@@ -40,6 +36,22 @@ def query_erp_info(db: Session, zongpai_no: str) -> dict:
     }
 
 
+def _erp_info_sql(db: Session) -> str:
+    dialect_name = db.bind.dialect.name if db.bind is not None else ""
+    if dialect_name == "postgresql":
+        return (
+            'SELECT "总排号", "排产号", "数量" '
+            'FROM "ERPAuto"."vw_productionContractData" '
+            'WHERE "总排号" = :zongpai_no '
+            "LIMIT 1"
+        )
+    return (
+        "SELECT TOP 1 [总排号], [排产号], [数量] "
+        "FROM [ERPAuto].[vw_productionContractData] "
+        "WHERE [总排号] = :zongpai_no"
+    )
+
+
 def get_box_info(db: Session, zongpai_no: str) -> dict:
     """获取装箱信息：排产号、数量、已有箱号明细。"""
     zongpai_no = zongpai_no.strip().upper()

config/settings.py

@@ -1,7 +1,7 @@
 from pathlib import Path
-from typing import Optional
+from typing import Literal
 from sqlalchemy.engine import URL
-from pydantic import BaseModel, Field
+from pydantic import BaseModel
 from pydantic_yaml import parse_yaml_raw_as
 
 
@@ -16,9 +16,20 @@ class SqlServerConfig(BaseModel):
     trust_server_certificate: str = "yes"
 
 
+class PostgreSqlConfig(BaseModel):
+    """PostgreSQL 连接配置"""
+    host: str
+    port: int = 5432
+    database: str
+    username: str
+    password: str
+
+
 class DatabaseConfig(BaseModel):
     """数据库配置"""
+    active: Literal["sql_server", "postgresql"] = "sql_server"
     sql_server: SqlServerConfig
+    postgresql: PostgreSqlConfig | None = None
 
 
 class Settings(BaseModel):
@@ -28,6 +39,11 @@ class Settings(BaseModel):
     @property
     def database_url(self) -> URL:
         """构建数据库连接 URL"""
+        if self.database.active == "postgresql":
+            return self._postgresql_url()
+        return self._sql_server_url()
+
+    def _sql_server_url(self) -> URL:
         conf = self.database.sql_server
         return URL.create(
             "mssql+pyodbc",
@@ -42,6 +58,19 @@ class Settings(BaseModel):
             },
         )
 
+    def _postgresql_url(self) -> URL:
+        conf = self.database.postgresql
+        if conf is None:
+            raise ValueError("已选择 postgresql，但未配置 database.postgresql")
+        return URL.create(
+            "postgresql+psycopg",
+            username=conf.username,
+            password=conf.password,
+            host=conf.host,
+            port=conf.port,
+            database=conf.database,
+        )
+
 
 def load_settings(config_path: str = "config/settings.yaml") -> Settings:
     """加载 YAML 配置文件"""

config/settings.yaml.example

@@ -1,5 +1,6 @@
 # 数据库配置
 database:
+  active: sql_server  # 可选: sql_server, postgresql
   sql_server:
     host: YOUR_DB_HOST
     port: 1433
@@ -8,3 +9,9 @@ database:
     password: YOUR_PASSWORD
     driver: "{ODBC Driver 18 for SQL Server}"
     trust_server_certificate: yes
+  postgresql:
+    host: YOUR_POSTGRES_HOST
+    port: 5432
+    database: YOUR_POSTGRES_DB_NAME
+    username: YOUR_POSTGRES_USERNAME
+    password: YOUR_POSTGRES_PASSWORD

requirements.txt

@@ -2,6 +2,7 @@ fastapi>=0.115.0
 uvicorn[standard]>=0.34.0
 sqlalchemy>=2.0.0
 pyodbc>=5.2.0
+psycopg[binary]>=3.2.0
 pydantic-settings>=2.0.0
 python-dotenv>=1.0.0
 pytest>=8.0.0

tests/fixtures/test_config.yaml

@@ -1,5 +1,6 @@
 # 测试配置
 database:
+  active: sql_server
   sql_server:
     host: localhost
     port: 1433
@@ -8,3 +9,9 @@ database:
     password: test_pass
     driver: "{ODBC Driver 18 for SQL Server}"
     trust_server_certificate: yes
+  postgresql:
+    host: localhost
+    port: 5432
+    database: TestDB
+    username: test_user
+    password: test_pass

tests/test_config.py

@@ -5,6 +5,7 @@ from config.settings import load_settings
 def test_load_settings_success():
     """测试成功加载配置文件"""
     settings = load_settings("tests/fixtures/test_config.yaml")
+    assert settings.database.active == "sql_server"
     assert settings.database.sql_server.port == 1433
     assert settings.database.sql_server.host == "localhost"
     assert settings.database.sql_server.database == "TestDB"
@@ -23,3 +24,14 @@ def test_database_url_property():
     assert "mssql+pyodbc" in str(url)
     assert "test_user" in str(url)
     assert "TestDB" in str(url)
+
+
+def test_postgresql_database_url_property():
+    """测试 PostgreSQL database_url 属性生成"""
+    settings = load_settings("tests/fixtures/test_config.yaml")
+    settings.database.active = "postgresql"
+    url = settings.database_url
+    assert url.drivername == "postgresql+psycopg"
+    assert url.host == "localhost"
+    assert url.port == 5432
+    assert url.database == "TestDB"