feat: transaction

src/coffees/coffees.module.ts

@@ -4,13 +4,14 @@ import { CoffeesService } from './coffees.service';
 import { TypeOrmModule } from '@nestjs/typeorm';
 import { Coffee } from './entities/coffee.entity';
 import { Flavor } from './entities/flavor.entity';
+import { Event } from '../events/entities/event.entity/event.entity';
 
 // nest g module 命令行创建 module
 // 也可以简写 nest g mo
 // 也可以简写 nest g mo moduleName
 
 @Module({
-  imports: [TypeOrmModule.forFeature([Coffee, Flavor])],
+  imports: [TypeOrmModule.forFeature([Coffee, Flavor, Event])],
   controllers: [CoffeesController],
   providers: [CoffeesService],
 })

src/coffees/coffees.service.ts

@@ -8,9 +8,10 @@ import { Coffee } from './entities/coffee.entity';
 import { CreateCoffeesDto } from './dto/create-coffees.dto/create-coffees.dto';
 import { UpdateCoffeesDto } from './dto/update--coffees.dto/update--coffees.dto';
 import { InjectRepository } from '@nestjs/typeorm';
-import { Repository } from 'typeorm';
+import { Connection, Repository } from 'typeorm';
 import { Flavor } from './entities/flavor.entity';
 import { PaginationQueryDto } from 'src/common/dto/pagination-query.dto/pagination-query.dto';
+import { Event } from '../events/entities/event.entity/event.entity';
 
 // nest generate service 命令行创建 controller
 // 简写：nest j s
@@ -22,6 +23,7 @@ export class CoffeesService {
     private readonly coffeeRepository: Repository<Coffee>,
     @InjectRepository(Flavor)
     private readonly flavorRepository: Repository<Flavor>,
+    private readonly connection: Connection,
   ) {}
 
   findAll(paginationQuery: PaginationQueryDto) {
@@ -79,6 +81,28 @@ export class CoffeesService {
     return this.coffeeRepository.remove(coffee);
   }
 
+  async recommendCoffee(coffee: Coffee) {
+    const queryRunner = this.connection.createQueryRunner();
+
+    await queryRunner.connect();
+    await queryRunner.startTransaction();
+
+    try {
+      coffee.recommendations++;
+      const recommendEvent = new Event();
+      recommendEvent.name = 'recommend_coffee';
+      recommendEvent.type = 'coffee';
+      recommendEvent.payload = { coffeeId: coffee.id };
+      await queryRunner.manager.save(coffee);
+      await queryRunner.manager.save(recommendEvent);
+      await queryRunner.commitTransaction();
+    } catch (err) {
+      await queryRunner.rollbackTransaction();
+    } finally {
+      await queryRunner.release();
+    }
+  }
+
   private async preloadFlavorsByNames(name: string): Promise<Flavor> {
     const existFlavor = await this.flavorRepository.findOneBy({ name });
     if (existFlavor) {

src/coffees/entities/coffee.entity.ts

@@ -19,6 +19,9 @@ export class Coffee {
   @Column()
   brand: string;
 
+  @Column({ default: 0 })
+  recommendations: number;
+
   // @Column('json', { nullable: true }) // 可选
   @JoinTable()
   // cascade: true 表示级联保存, 保存coffee的时候, 会级联保存flavor

src/events/entities/event.entity/event.entity.ts

@@ -0,0 +1,18 @@
+import { Column, Entity, Index, PrimaryGeneratedColumn } from 'typeorm';
+
+@Index(['name', 'type']) // 复合索引
+@Entity()
+export class Event {
+  @PrimaryGeneratedColumn()
+  id: number;
+
+  @Column()
+  type: string;
+
+  @Index() // 索引
+  @Column()
+  name: string;
+
+  @Column('json')
+  payload: Record<string, any>;
+}