SQLModel Todo Task Model

Overview

This skill provides the standardized SQLModel Task class for Todo applications with proper user isolation. It enforces multi-user isolation via user_id and includes all required fields for a complete Todo task management system.

Core Task Model

Standard Task Class Definition

Use this exact SQLModel Task class unless explicitly overridden:

from sqlmodel import SQLModel, Field, Column
from datetime import datetime
from typing import Optional
from sqlalchemy import DateTime


class Task(SQLModel, table=True):
    # Enforces multi-user isolation via user_id
    id: Optional[int] = Field(default=None, primary_key=True)
    user_id: str = Field(index=True)  # Foreign key to user, indexed for performance
    title: str = Field(max_length=200)  # Required, max_length=200
    description: Optional[str] = None
    completed: bool = Field(default=False)
    created_at: datetime = Field(default_factory=datetime.utcnow)
    updated_at: datetime = Field(default_factory=datetime.utcnow, sa_column=Column(DateTime(timezone=True), onupdate=datetime.utcnow))

Field Specifications

Required Fields

• •id: Optional[int] = Field(default=None, primary_key=True)
• •user_id: str - Foreign key to user, indexed for performance
• •title: str - Required field with max_length=200

Optional Fields

• •description: Optional[str] = None
• •completed: bool = Field(default=False) - Tracks task completion status
• •created_at: datetime = Field(default_factory=datetime.utcnow) - Timestamp of creation
• •updated_at: datetime = Field(default_factory=datetime.utcnow, sa_column=Column(DateTime(timezone=True), onupdate=datetime.utcnow)) - Timestamp of last update

Indexing Strategy

Always include indexes for performance:

• •Index on user_id for efficient multi-user filtering
• •Index on completed for status-based queries

Relationship Pattern

When defining relationships with User model:

from sqlmodel import SQLModel, Field, Relationship
from datetime import datetime
from typing import Optional
from sqlalchemy import DateTime


class Task(SQLModel, table=True):
    # Enforces multi-user isolation via user_id
    id: Optional[int] = Field(default=None, primary_key=True)
    user_id: str = Field(index=True, foreign_key="user.id")
    title: str = Field(max_length=200)
    description: Optional[str] = None
    completed: bool = Field(default=False, index=True)
    created_at: datetime = Field(default_factory=datetime.utcnow)
    updated_at: datetime = Field(default_factory=datetime.utcnow, sa_column=Column(DateTime(timezone=True), onupdate=datetime.utcnow))

    # Relationship to User if needed
    # user: "User" = Relationship(back_populates="tasks")

Multi-User Isolation Enforcement

⚠️ Critical: The user_id field is essential for enforcing multi-user isolation. Every database query must filter by user_id to prevent data leakage between users.

Example query pattern:

from sqlmodel import select

# Correct - includes user_id filter
user_tasks = session.exec(
    select(Task)
    .where(Task.user_id == current_user.id)
).all()

Validation Checklist

Before implementing the Task model:

• • Uses SQLModel with table=True
• • Includes id field with primary_key=True
• • Includes user_id field with index for multi-user isolation
• • Title has max_length=200 constraint
• • Completed field has index for performance
• • Has both created_at and updated_at timestamps
• • Updated_at field has onupdate trigger
• • Comment "# Enforces multi-user isolation via user_id" is included