Setup Drizzle for backend integration

.gitignore

@@ -1 +1,3 @@
 .env
+.idea
+.vscode

backend/drizzle.config.ts

@@ -0,0 +1,16 @@
+import { defineConfig } from 'drizzle-kit';
+
+if (!process.env.DATABASE_URL) {
+  throw new Error('DATABASE_URL environment variable is required');
+}
+
+export default defineConfig({
+  dialect: 'postgresql',
+  schema: './src/database/schema/*.ts',
+  out: './drizzle',
+  dbCredentials: {
+    url: process.env.DATABASE_URL,
+  },
+  strict: true,
+  verbose: true,
+});

backend/package.json

@@ -19,12 +19,18 @@
     "test:watch": "jest --watch",
     "test:cov": "jest --coverage",
     "test:debug": "node --inspect-brk -r tsconfig-paths/register -r ts-node/register node_modules/.bin/jest --runInBand",
-    "test:e2e": "jest --config ./test/jest-e2e.json"
+    "test:e2e": "jest --config ./test/jest-e2e.json",
+    "db:generate": "drizzle-kit generate",
+    "db:migrate": "drizzle-kit migrate",
+    "db:push": "drizzle-kit push",
+    "db:studio": "drizzle-kit studio"
   },
   "dependencies": {
     "@nestjs/common": "^11.0.1",
     "@nestjs/core": "^11.0.1",
     "@nestjs/platform-express": "^11.0.1",
+    "drizzle-orm": "^0.45.2",
+    "pg": "^8.20.0",
     "reflect-metadata": "^0.2.2",
     "rxjs": "^7.8.1"
   },
@@ -37,7 +43,9 @@
     "@types/express": "^5.0.0",
     "@types/jest": "^30.0.0",
     "@types/node": "^22.10.7",
+    "@types/pg": "^8.20.0",
     "@types/supertest": "^6.0.2",
+    "drizzle-kit": "^0.31.10",
     "eslint": "^9.18.0",
     "eslint-config-prettier": "^10.0.1",
     "eslint-plugin-prettier": "^5.2.2",

backend/src/app.module.ts

@@ -1,9 +1,11 @@
 import { Module } from '@nestjs/common';
+
 import { AppController } from './app.controller';
 import { AppService } from './app.service';
+import { DatabaseModule } from './database/database.module';
 
 @Module({
-  imports: [],
+  imports: [DatabaseModule],
   controllers: [AppController],
   providers: [AppService],
 })

backend/src/database/database.module.ts

@@ -0,0 +1,38 @@
+import { Global, Inject, Module, OnModuleDestroy } from '@nestjs/common';
+import { drizzle, NodePgDatabase } from 'drizzle-orm/node-postgres';
+import { Pool } from 'pg';
+
+import * as schema from './schema';
+
+export const DATABASE_POOL = Symbol('DATABASE_POOL');
+export const DRIZZLE = Symbol('DRIZZLE');
+
+export type Database = NodePgDatabase<typeof schema>;
+
+@Global()
+@Module({
+  providers: [
+    {
+      provide: DATABASE_POOL,
+      useFactory: (): Pool => {
+        if (!process.env.DATABASE_URL) {
+          throw new Error('DATABASE_URL environment variable is required');
+        }
+        return new Pool({ connectionString: process.env.DATABASE_URL });
+      },
+    },
+    {
+      provide: DRIZZLE,
+      inject: [DATABASE_POOL],
+      useFactory: (pool: Pool): Database => drizzle(pool, { schema }),
+    },
+  ],
+  exports: [DRIZZLE],
+})
+export class DatabaseModule implements OnModuleDestroy {
+  constructor(@Inject(DATABASE_POOL) private readonly pool: Pool) {}
+
+  async onModuleDestroy(): Promise<void> {
+    await this.pool.end();
+  }
+}

backend/src/database/schema/index.ts

@@ -0,0 +1 @@
+export {};