Epic 1, Story 1.4: Database Schema Definition with Prisma

- Installed Prisma and @prisma/client in backend/ directory
- Initialized Prisma with PostgreSQL provider (Prisma 7.x)
- Created prisma/schema.prisma with Book and ReadingLog models
- Configured prisma.config.ts with DATABASE_URL from environment
- Added .gitignore for Prisma-generated files

Book model includes:
- All required fields (id, title, author, totalPages, coverUrl, deadlineDate, isPrimary, status)
- Timestamps (createdAt, updatedAt)
- Indexes on deadlineDate and status for query performance
- One-to-many relationship with ReadingLog

ReadingLog model includes:
- All required fields (id, bookId, logDate, currentPage)
- Timestamps (createdAt, updatedAt)
- Foreign key relationship to Book with cascade delete
- Unique constraint on (bookId, logDate) - one entry per book per day
- Indexes on bookId and logDate for query performance

All acceptance criteria met:
✅ Prisma installed in backend/
✅ Initialized with PostgreSQL provider
✅ schema.prisma defines Book and ReadingLog models
✅ Appropriate indexes for performance
✅ One-to-many relationship defined
✅ Unique constraint ensures one log entry per book per day

Schema validated with npx prisma format

🤖 Generated with Claude Code (https://claude.com/claude-code)

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

backend/.gitignore

@@ -0,0 +1,5 @@
+node_modules
+# Keep environment variables out of version control
+.env
+
+/src/generated/prisma

backend/eslint.config.js

@@ -0,0 +1,21 @@
+const globals = require('globals');
+
+module.exports = [
+  {
+    files: ['**/*.js'],
+    languageOptions: {
+      ecmaVersion: 2022,
+      sourceType: 'commonjs',
+      globals: {
+        ...globals.node,
+      },
+    },
+    rules: {
+      'no-unused-vars': ['error', { argsIgnorePattern: '^_' }],
+      'no-console': 'off',
+    },
+  },
+  {
+    ignores: ['node_modules/**', 'dist/**'],
+  },
+];

backend/package.json

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+{
+  "name": "backend",
+  "version": "1.0.0",
+  "description": "Book Reading Tracker - Backend API",
+  "main": "src/server.js",
+  "scripts": {
+    "dev": "nodemon src/server.js",
+    "start": "node src/server.js",
+    "lint": "eslint .",
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "@prisma/client": "^7.1.0",
+    "cors": "^2.8.5",
+    "dotenv": "^17.2.3",
+    "express": "^5.2.1",
+    "express-validator": "^7.3.1",
+    "helmet": "^8.1.0",
+    "prisma": "^7.1.0"
+  },
+  "devDependencies": {
+    "eslint": "^9.39.1",
+    "globals": "^16.5.0",
+    "nodemon": "^3.1.11"
+  }
+}

backend/prisma.config.ts

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+// This file was generated by Prisma and assumes you have installed the following:
+// npm install --save-dev prisma dotenv
+import "dotenv/config";
+import { defineConfig, env } from "prisma/config";
+
+export default defineConfig({
+  schema: "prisma/schema.prisma",
+  migrations: {
+    path: "prisma/migrations",
+  },
+  datasource: {
+    url: env("DATABASE_URL"),
+  },
+});

backend/prisma/schema.prisma

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+// This is your Prisma schema file,
+// learn more about it in the docs: https://pris.ly/d/prisma-schema
+
+generator client {
+  provider = "prisma-client-js"
+}
+
+datasource db {
+  provider = "postgresql"
+}
+
+model Book {
+  id           Int      @id @default(autoincrement())
+  title        String   @db.VarChar(500)
+  author       String?  @db.VarChar(500)
+  totalPages   Int
+  coverUrl     String?  @db.VarChar(1000)
+  deadlineDate DateTime @db.Date
+  isPrimary    Boolean  @default(false)
+  status       String   @default("reading") @db.VarChar(50)
+  createdAt    DateTime @default(now())
+  updatedAt    DateTime @updatedAt
+
+  readingLogs ReadingLog[]
+
+  @@index([deadlineDate])
+  @@index([status])
+}
+
+model ReadingLog {
+  id          Int      @id @default(autoincrement())
+  bookId      Int
+  logDate     DateTime @db.Date
+  currentPage Int
+  createdAt   DateTime @default(now())
+  updatedAt   DateTime @updatedAt
+
+  book Book @relation(fields: [bookId], references: [id], onDelete: Cascade)
+
+  @@unique([bookId, logDate])
+  @@index([bookId])
+  @@index([logDate])
+}

backend/src/server.js

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+require('dotenv').config();
+const express = require('express');
+const cors = require('cors');
+const helmet = require('helmet');
+
+const app = express();
+
+// Middleware
+app.use(helmet());
+app.use(
+  cors({
+    origin: process.env.CORS_ORIGIN || 'http://localhost:5173',
+    credentials: true,
+  })
+);
+app.use(express.json());
+
+// Health check endpoint
+app.get('/api/health', (req, res) => {
+  res.json({
+    status: 'ok',
+    timestamp: new Date().toISOString(),
+  });
+});
+
+// Error handling middleware
+app.use((err, req, res, _next) => {
+  console.error('Error:', err);
+
+  // Validation errors (from express-validator)
+  if (err.errors && Array.isArray(err.errors)) {
+    return res.status(400).json({
+      error: 'Validation failed',
+      details: err.errors,
+    });
+  }
+
+  // Default error response
+  res.status(err.statusCode || 500).json({
+    error: err.message || 'Internal server error',
+  });
+});
+
+// Start server
+const PORT = process.env.API_PORT || 3000;
+app.listen(PORT, () => {
+  console.log(`Server running on http://localhost:${PORT}`);
+  console.log(`Health check: http://localhost:${PORT}/api/health`);
+});
+
+module.exports = app;