NestJS huunganika kwa usafi na databases kupitia ORMs — mara nyingi zaidi TypeORM (integration rasmi ya @nestjs/typeorm) na Prisma (ORM ya kisasa, salama kwa aina inayotumika kupitia custom service). Zote zinaendana na muundo wa module/provider/DI wa NestJS.
({
: [
.({
: ,
: process..,
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}),
.([]),
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})
{}
// 2. define an entity (maps to a table)
@Entity()
export class User {
@PrimaryGeneratedColumn() id: number;
@Column() name: string;
@Column({ unique: true }) email: string;
}
// 3. inject the repository into a service
@Injectable()
export class UsersService {
constructor(
@InjectRepository(User) private usersRepo: Repository<User>,
) {}
findAll() { return this.usersRepo.find(); }
findOne(id: number) { return this.usersRepo.findOneBy({ id }); }
create(data: Partial<User>) { return this.usersRepo.save(data); }
}
TypeORM hutumia @Entity classes (zinazounganishwa na tables) na injectable Repositorys kwa queries — zikiendana na muundo wa DI wa NestJS kiasili kupitia @InjectRepository.
// 1. a PrismaService wraps the Prisma client (and manages connection lifecycle)
@Injectable()
export class PrismaService extends PrismaClient implements OnModuleInit {
async onModuleInit() { await this.$connect(); } // connect on startup
}
// 2. inject it and use the type-safe client
@Injectable()
export class UsersService {
constructor(private prisma: PrismaService) {}
findAll() { return this.prisma.user.findMany(); }
findOne(id: number) { return this.prisma.user.findUnique({ where: { id } }); }
create(data) { return this.prisma.user.create({ data }); }
}
Prisma huzalisha client iliyo salama kabisa kwa aina kutoka faili ya schema; unaifunika katika PrismaService inayoweza kuingizwa na kuitumia katika services zako.
⚠️ NEVER use `synchronize: true` (TypeORM) in production — it auto-alters your schema
and can DROP data. Use MIGRATIONS (version-controlled schema changes) instead.
Prisma: prisma migrate dev/deploy manages schema changes via migration files.
TypeORM → repository/active-record patterns, decorators, mature, official Nest integration
Prisma → schema-first, excellent type safety, great DX, growing popularity
Integration ya database ni muhimu — karibu kila back-end huhifadhi data, na kuelewa jinsi ya kuunganisha database na NestJS kwa njia ya kawaida ni maarifa muhimu ya kivitendo.
ORMs zote mbili kuu zinaendana na usanifu wa NestJS kwa usafi: TypeORM kupitia module rasmi ya @nestjs/typeorm (kuweka mipangilio ya connections, kufafanua @Entity classes, kuingiza Repositorys kupitia DI) na Prisma kupitia PrismaService inayoweza kuingizwa iliyofunikwa (ikitoa usalama bora wa aina).
Kujua jinsi ya kuanzisha connection, kufafanua models, na kuingiza tabaka la ufikiaji wa data ndani ya services — kuweka database logic ndani ya services, tofauti na controllers — ni msingi kwa kujenga programu halisi za NestJS.
Muhimu zaidi, kuelewa kanuni ya migrations-badala-ya-synchronize (kamwe usisawazishe schema kiotomatiki katika production, ambapo inaweza kuharibu data, bali tumia migrations zinazodhibitiwa kwa version) ni mazoezi muhimu ya usalama wa production.
Hili ni nyenzo ya kila siku, inayopaswa kujulikana, kwa kuwa uhifadhi wa data ni msingi wa maendeleo ya back-end na ORM integration ndiyo jinsi programu za NestJS zinavyohifadhi na kurejesha data zao kwa vitendo.