AgentSkillsCN

Db Schema

数据库模式

SKILL.md

Database Schema Generator

Critical for Phases: II, III, V

Generates SQLModel classes, relationships, and Neon DB migrations from entity descriptions.

Usage

code
/gen.db-schema "<entity descriptions>"

# Example:
/gen.db-schema "User entity with id, email, password_hash, created_at. Todo entity with id, title, description, completed, user_id (FK to User), created_at, updated_at. One-to-many User to Todos"

What It Generates

  • •SQLModel class definitions with proper field types
  • •Foreign key relationships with cascade rules
  • •Indexes for performance
  • •Neon DB migration file
  • •Seed data for testing
  • •Base model with common fields

Output Structure

code
phase-XX/src/models/
  ├── base.py              # Base SQLModel and DB session
  ├── user.py              # User SQLModel
  ├── todo.py              # Todo SQLModel
  └── migrations/
      ├── 001_create_initial_tables.sql
      └── 002_add_indexes.sql

Features

  • •UUID primary keys
  • •Timestamp fields (created_at, updated_at) with auto-update
  • •Soft delete support
  • •Enum fields for status
  • •Cascade delete relationships
  • •Snake_case table naming
  • •Proper typing with Optional

Phase Usage

  • •Phase II: Users, Todos tables
  • •Phase III: Conversations, Messages tables
  • •Phase V: Event tables, TaskHistory tables

Example Output

python
from typing import Optional
from sqlmodel import SQLModel, Field, Relationship
from datetime import datetime
from uuid import uuid4

class User(SQLModel, table=True):
    __tablename__ = "users"

    id: UUID = Field(default_factory=uuid4, primary_key=True)
    email: str = Field(unique=True, index=True, max_length=255)
    password_hash: str = Field(max_length=255)
    created_at: datetime = Field(default_factory=datetime.utcnow)

    todos: list["Todo"] = Relationship(back_populates="user")

class Todo(SQLModel, table=True):
    __tablename__ = "todos"

    id: UUID = Field(default_factory=uuid4, primary_key=True)
    title: str = Field(max_length=500)
    description: Optional[str] = Field(default=None, max_length=2000)
    completed: bool = Field(default=False)
    user_id: UUID = Field(foreign_key="users.id")
    created_at: datetime = Field(default_factory=datetime.utcnow)
    updated_at: datetime = Field(default_factory=datetime.utcnow)

    user: User = Relationship(back_populates="todos")

Best Practices Applied

  • •Pydantic v2 style models
  • •Proper typing with Optional
  • •Field constraints (max_length, unique)
  • •Cascade delete relationships
  • •Index on foreign keys and email
  • •UTC timestamps
  • •UUID for security