> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/Celaya55/app-cr/llms.txt
> Use this file to discover all available pages before exploring further.

# Database Schema

> Complete database schema documentation with models, fields, and relationships

## Overview

App CR uses Prisma ORM with PostgreSQL 15 as the database. The schema defines two core models: **User** and **Task**, with a one-to-many relationship.

## Schema Configuration

```prisma theme={null}
generator client {
  provider = "prisma-client-js"
}

datasource db {
  provider = "postgresql"
  url      = env("DATABASE_URL")
}
```

<ParamField path="generator.provider" type="string" default="prisma-client-js">
  Generates the Prisma Client for JavaScript/TypeScript applications
</ParamField>

<ParamField path="datasource.provider" type="string" default="postgresql">
  Database provider (PostgreSQL 15)
</ParamField>

<ParamField path="datasource.url" type="string" required>
  Database connection URL from `DATABASE_URL` environment variable
</ParamField>

***

## User Model

The User model represents application users who can create and manage tasks.

```prisma theme={null}
model User {
  id        Int      @id @default(autoincrement())
  email     String   @unique
  password  String
  tasks     Task[]
}
```

### Fields

<ResponseField name="id" type="Int" required>
  Primary key with auto-increment

  **Attributes:**

  * `@id` - Primary key constraint
  * `@default(autoincrement())` - Auto-generated sequential ID
</ResponseField>

<ResponseField name="email" type="String" required>
  User's email address (unique across all users)

  **Attributes:**

  * `@unique` - Unique constraint enforced at database level

  **Validation:** Must be a valid email format
</ResponseField>

<ResponseField name="password" type="String" required>
  Hashed password for user authentication

  **Security:** Store only bcrypt/argon2 hashed passwords, never plaintext
</ResponseField>

<ResponseField name="tasks" type="Task[]">
  One-to-many relationship with Task model

  **Relation:** A user can have multiple tasks
</ResponseField>

### Database Table

```sql theme={null}
CREATE TABLE "User" (
    "id" SERIAL NOT NULL,
    "email" TEXT NOT NULL,
    "password" TEXT NOT NULL,
    CONSTRAINT "User_pkey" PRIMARY KEY ("id")
);

CREATE UNIQUE INDEX "User_email_key" ON "User"("email");
```

***

## Task Model

The Task model represents todo items created by users.

```prisma theme={null}
model Task {
  id          Int      @id @default(autoincrement())
  title       String
  description String?
  completed   Boolean  @default(false)
  userId      Int
  author      User     @relation(fields: [userId], references: [id])
}
```

### Fields

<ResponseField name="id" type="Int" required>
  Primary key with auto-increment

  **Attributes:**

  * `@id` - Primary key constraint
  * `@default(autoincrement())` - Auto-generated sequential ID
</ResponseField>

<ResponseField name="title" type="String" required>
  Task title or summary

  **Validation:** Required field, cannot be null or empty
</ResponseField>

<ResponseField name="description" type="String?">
  Optional detailed description of the task

  **Nullable:** Can be null/undefined
</ResponseField>

<ResponseField name="completed" type="Boolean" required>
  Task completion status

  **Attributes:**

  * `@default(false)` - New tasks are incomplete by default

  **Values:** `true` (completed) or `false` (pending)
</ResponseField>

<ResponseField name="userId" type="Int" required>
  Foreign key referencing the User who created this task

  **Relation:** Links to `User.id`
</ResponseField>

<ResponseField name="author" type="User" required>
  Many-to-one relationship with User model

  **Attributes:**

  * `@relation(fields: [userId], references: [id])` - Foreign key relationship

  **Behavior:**

  * `ON DELETE RESTRICT` - Cannot delete user if they have tasks
  * `ON UPDATE CASCADE` - Updates propagate to tasks
</ResponseField>

### Database Table

```sql theme={null}
CREATE TABLE "Task" (
    "id" SERIAL NOT NULL,
    "title" TEXT NOT NULL,
    "description" TEXT,
    "completed" BOOLEAN NOT NULL DEFAULT false,
    "userId" INTEGER NOT NULL,
    CONSTRAINT "Task_pkey" PRIMARY KEY ("id")
);

ALTER TABLE "Task" ADD CONSTRAINT "Task_userId_fkey" 
  FOREIGN KEY ("userId") REFERENCES "User"("id") 
  ON DELETE RESTRICT ON UPDATE CASCADE;
```

***

## Relationships

### User ↔ Task (One-to-Many)

<Steps>
  <Step title="User has many Tasks">
    Each user can create multiple tasks through the `tasks` relation field

    ```typescript theme={null}
    const userWithTasks = await prisma.user.findUnique({
      where: { id: 1 },
      include: { tasks: true }
    });
    ```
  </Step>

  <Step title="Task belongs to User">
    Each task belongs to exactly one user through the `author` relation and `userId` foreign key

    ```typescript theme={null}
    const taskWithAuthor = await prisma.task.findUnique({
      where: { id: 1 },
      include: { author: true }
    });
    ```
  </Step>

  <Step title="Referential Integrity">
    Foreign key constraint ensures data integrity:

    * Cannot create task with non-existent userId
    * Cannot delete user who has tasks (RESTRICT)
    * Updating user.id cascades to task.userId (CASCADE)
  </Step>
</Steps>

***

## Schema File Location

```bash theme={null}
~/workspace/source/backend/prisma/schema.prisma
```

## Working with the Schema

<CodeGroup>
  ```bash Generate Client theme={null}
  npx prisma generate
  ```

  ```bash Format Schema theme={null}
  npx prisma format
  ```

  ```bash Validate Schema theme={null}
  npx prisma validate
  ```

  ```bash View in Studio theme={null}
  npx prisma studio
  ```
</CodeGroup>

<Note>
  After modifying the schema, always run `prisma generate` to update the Prisma Client types.
</Note>

***

## Next Steps

<CardGroup cols={2}>
  <Card title="Run Migrations" icon="arrows-rotate" href="/database/migrations">
    Learn how to apply schema changes to your database
  </Card>

  <Card title="Database Setup" icon="wrench" href="/database/setup">
    Configure database connection and environment
  </Card>
</CardGroup>