fix: 修复Task 3数据库模型问题

- 修复导入路径：从绝对导入改为相对导入
- 添加外键约束：Project.created_by添加ForeignKey，使用ON DELETE RESTRICT
- 添加索引：为常用查询字段添加index=True（username, email, department, role, project_no, engineering_type等）
- 优化Enum使用：创建UserRoleEnum和AdjustmentEnum类替代字符串枚举
- 添加关系映射：User.created_projects和Project.creator建立双向关系
- 添加User.created_by字段：保持与Project表一致性

backend/src/models/project.py

@@ -1,7 +1,13 @@
 # backend/src/models/project.py
-from sqlalchemy import Column, Integer, String, Text, Date, Numeric, DateTime, Enum
+from sqlalchemy import Column, Integer, String, Text, Date, Numeric, DateTime, Enum, ForeignKey
 from sqlalchemy.sql import func
-from config.database import Base
+from sqlalchemy.orm import relationship
+from ..config.database import Base
+
+
+class AdjustmentEnum(str, Enum):
+    yes = "是"
+    no = "否"
 
 
 class Project(Base):
@@ -10,7 +16,7 @@ class Project(Base):
     id = Column(Integer, primary_key=True, autoincrement=True, comment="项目ID")
 
     # 基础信息
-    project_no = Column(String(50), unique=True, nullable=False, comment="合同编号")
+    project_no = Column(String(50), unique=True, nullable=False, index=True, comment="合同编号")
     power_contract_no = Column(String(100), comment="供电局项目合同编号")
     name = Column(String(200), nullable=False, comment="项目名称")
     subitem_count = Column(Integer, default=0, comment="子项个数")
@@ -21,28 +27,28 @@ class Project(Base):
     settlement_amount = Column(Numeric(15, 2), comment="结算金额（万元）")
     total_cost_estimated = Column(Numeric(15, 2), comment="总成本测算")
     voltage_level = Column(String(50), comment="工程电压等级")
-    engineering_type = Column(String(50), comment="工程类别")
+    engineering_type = Column(String(50), index=True, comment="工程类别")
-    owner_unit = Column(String(200), comment="业主单位")
+    owner_unit = Column(String(200), index=True, comment="业主单位")
     owner_contact = Column(String(200), comment="业主联系人及电话")
     bidding_type = Column(String(50), comment="中标形式")
-    signing_date = Column(Date, comment="签订日期")
+    signing_date = Column(Date, index=True, comment="签订日期")
-    start_date = Column(Date, comment="开工日期")
+    start_date = Column(Date, index=True, comment="开工日期")
-    planned_end_date = Column(Date, comment="计划竣工日期")
+    planned_end_date = Column(Date, index=True, comment="计划竣工日期")
-    actual_end_date = Column(Date, comment="实际竣工日期")
+    actual_end_date = Column(Date, index=True, comment="实际竣工日期")
 
     # 质保信息
     warranty_amount = Column(Numeric(15, 2), default=0, comment="质保金（万元）")
-    warranty_expiry_date = Column(Date, comment="质保期截止日")
+    warranty_expiry_date = Column(Date, index=True, comment="质保期截止日")
     actual_warranty_refund_date = Column(Date, comment="实际退质保金日期")
 
     # 项目信息
-    project_department = Column(String(100), comment="所属项目部")
+    project_department = Column(String(100), index=True, comment="所属项目部")
     project_leader = Column(String(200), comment="项目负责人及电话")
     payment_method = Column(Text, comment="工程款拨付方式")
 
     # 成本控制
     total_cost_control = Column(Numeric(15, 2), comment="总体成本（控制）")
-    is_adjusted = Column(Enum("是", "否"), default="否", comment="是否调整")
+    is_adjusted = Column(Enum(AdjustmentEnum), default=AdjustmentEnum.no, index=True, comment="是否调整")
     labor_cost_control = Column(Numeric(15, 2), comment="人工成本（控制）")
     labor_cost_planned = Column(Numeric(15, 2), comment="农民工工资（计划）")
     labor_cost_paid = Column(Numeric(15, 2), comment="农民工工资（实付）")
@@ -88,7 +94,7 @@ class Project(Base):
     remarks = Column(Text, comment="备注")
 
     # 系统字段
-    created_by = Column(Integer, nullable=False, comment="创建人ID")
+    created_by = Column(Integer, ForeignKey("users.id", ondelete="RESTRICT"), nullable=False, index=True, comment="创建人ID")
     created_at = Column(
         DateTime,
         server_default=func.now(),
@@ -100,3 +106,5 @@ class Project(Base):
         onupdate=func.now(),
         comment="更新时间",
     )
+
+    creator = relationship("User", back_populates="created_projects")

backend/src/models/user.py

@@ -1,21 +1,29 @@
 # backend/src/models/user.py
 from sqlalchemy import Column, Integer, String, Boolean, DateTime, Enum
 from sqlalchemy.sql import func
-from config.database import Base
+from sqlalchemy.orm import relationship
+from ..config.database import Base
+
+
+class UserRoleEnum(str, Enum):
+    admin = "admin"
+    market = "market"
+    other = "other"
 
 
 class User(Base):
     __tablename__ = "users"
 
     id = Column(Integer, primary_key=True, autoincrement=True, comment="用户ID")
-    username = Column(String(50), unique=True, nullable=False, comment="用户名")
+    username = Column(String(50), unique=True, nullable=False, index=True, comment="用户名")
     password_hash = Column(String(255), nullable=False, comment="密码哈希")
     real_name = Column(String(100), nullable=False, comment="真实姓名")
-    department = Column(String(50), nullable=False, comment="部门")
+    department = Column(String(50), nullable=False, index=True, comment="部门")
-    role = Column(Enum("admin", "market", "other"), nullable=False, comment="角色")
+    role = Column(Enum(UserRoleEnum), nullable=False, index=True, comment="角色")
-    email = Column(String(100), unique=True, comment="邮箱")
+    email = Column(String(100), unique=True, index=True, comment="邮箱")
     phone = Column(String(20), comment="电话")
-    is_active = Column(Boolean, default=True, comment="是否激活")
+    is_active = Column(Boolean, default=True, index=True, comment="是否激活")
+    created_by = Column(Integer, comment="创建人ID")
     created_at = Column(
         DateTime,
         server_default=func.now(),
@@ -27,3 +35,6 @@ class User(Base):
         onupdate=func.now(),
         comment="更新时间",
     )
+
+    creator = relationship("User", remote_side="User.id", backref="created_users")
+    created_projects = relationship("Project", back_populates="creator", cascade="all, delete-orphan")