Extending Repositories

Overview

Generated repositories inherit from SolidBaseRepository<T>, which already:

• wraps TypeORM with metadata-aware behavior,
• enforces query-level access control via SecurityRuleRepository,
• provides contextual access with RequestContextService, and
• overrides the default TypeORM find methods (find, findOne, findAndCount, etc.) so they remain security-aware.

Why extend?
To keep business-specific queries out of services/controllers and in a single, testable, composable layer.

Extending repositories lets you:

• write expressive methods using simple find* calls (since they are already overridden to respect security rules),
• centralize complex joins or custom query builder logic when needed,
• reuse the same queries across multiple services, and
• maintain a clean separation between data access and business logic.

---

Step-by-step: add a custom method

1) Add a method using find

Most cases can be expressed with find/findOne since they’re already security-scoped.

Repository: add custom find-based method

import { Injectable } from '@nestjs/common';
import { RequestContextService, SecurityRuleRepository, SolidBaseRepository } from '@solidxai/core';
import { DataSource } from 'typeorm';
import { FeeType } from '../entities/fee-type.entity';

@Injectable()
export class FeeTypeRepository extends SolidBaseRepository<FeeType> {
  constructor(
    readonly dataSource: DataSource,
    readonly requestContextService: RequestContextService,
    readonly securityRuleRepository: SecurityRuleRepository,
  ) {
    super(FeeType, dataSource, requestContextService, securityRuleRepository);
  }

  /**
   * Example: find all active fee types for a given institute.
   * Uses overridden `find` so security rules apply automatically.
   */
  async findActiveByInstitute(instituteId: number): Promise<FeeType[]> {
    return this.find({
      where: {
        institute: { id: instituteId },
        isActive: true,
      },
      order: { displayOrder: 'ASC' },
    });
  }

  /**
   * Example: find one by code.
   */
  async findByCode(code: string): Promise<FeeType | null> {
    return this.findOne({ where: { code } });
  }
}

---

2) Add a method using Query Builder

For more complex cases (aggregations, raw joins, advanced conditions), fall back to createQueryBuilder().

Repository: add query builder method

async totalsByCategory(instituteId: number) {
  const qb = this.createQueryBuilder('ft')
    .innerJoin('ft.institute', 'inst', 'inst.id = :instituteId', { instituteId })
    .leftJoin('ft.feeItems', 'fi')
    .select('ft.category', 'category')
    .addSelect('COUNT(fi.id)', 'items')
    .addSelect('COALESCE(SUM(fi.amount), 0)', 'total')
    .groupBy('ft.category')
    .orderBy('ft.category', 'ASC');

  return qb.getRawMany<{ category: string; items: string; total: string }>();
}

---

3) Consume your custom repository methods

Service: use find-based and query builder methods

import { Injectable } from '@nestjs/common';
import { FeeTypeRepository } from './repositories/fee-type.repository';

@Injectable()
export class FeesService {
  constructor(private readonly feeTypeRepo: FeeTypeRepository) {}

  listActive(instituteId: number) {
    return this.feeTypeRepo.findActiveByInstitute(instituteId);
  }

  getTotals(instituteId: number) {
    return this.feeTypeRepo.totalsByCategory(instituteId);
  }
}

---

Best practices

• Prefer find / findOne / findAndCount when possible. They are overridden in SolidBaseRepository to remain security-aware and easier to read.
• Use createQueryBuilder() only for advanced scenarios (aggregations, raw SQL, unions).
• Keep authorization checks in services/guards. Repositories should stay focused on data access.
• Return typed results (entities for reads, raw objects for aggregates).
• Unit-test repository methods to validate filtering, ordering, and joins.

---

Quick reference

Example: security-aware find

await feeTypeRepo.find({
  where: { isActive: true },
  order: { displayOrder: 'ASC' },
  relations: ['institute'],
});

Example: fallback to query builder

await feeTypeRepo.totalsByCategory(1);