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Repository Layer Overview

The repository layer provides data access abstraction between services and the database.

Purpose​

Repositories handle:

  • Database queries and mutations
  • Data mapping between database and domain entities
  • SQL composition
  • No business logic

Standard Pattern​

export class FundRepository {
  constructor(private db: ProductionDBClient) {}

  async create(data: CreateFundRequest): Promise<FundEntity> {
    const [fund] = await this.db.insert(fundsTable).values(data).returning();
    return fund;
  }

  async findById(id: number): Promise<FundEntity | null> {
    const [fund] = await this.db
      .select()
      .from(fundsTable)
      .where(eq(fundsTable.id, id));
    return fund || null;
  }
}

See Repository Pattern for detailed documentation.