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/package.json

@@ -13,11 +13,13 @@
   "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"
+    "helmet": "^8.1.0",
+    "prisma": "^7.1.0"
   },
   "devDependencies": {
     "eslint": "^9.39.1",

backend/prisma.config.ts

@@ -0,0 +1,14 @@
+// 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

@@ -0,0 +1,43 @@
+// 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])
+}