Prisma service using knex migrations.

prisma.service.ts

import { Injectable, OnModuleDestroy, OnModuleInit } from '@nestjs/common';
import { PrismaClient } from '@prisma/client';
import knex from 'knex';
import knexfile from './knexfile';

@Injectable()
export class PrismaService extends PrismaClient implements OnModuleInit, OnModuleDestroy {
  /**
   * Waits for the database to be available.
   */
  private async waitForDatabase(): Promise<void> {
    while (true) {
      try {
        const database = knex(knexfile);
        await database.raw('SELECT 1 + 1;');
        await database.destroy();
        break;
      } catch (error) {
        // Database connection failed
        await new Promise((resolve) => setTimeout(resolve, 1500));
      }
    }
  }

  /**
   * Run migrations.
   */
  private async runMigrations(): Promise<void> {
    const database = knex(knexfile);
    const [, migrations]: [null, { file: string; directory: string }[]] = await database.migrate.list();
    if (migrations.length > 0) {
      await database.migrate.latest();
    }
    await database.destroy();
  }

  async onModuleInit(): Promise<void> {
    await this.waitForDatabase();
    await this.runMigrations();
    await this.$connect();
  }

  async onModuleDestroy(): Promise<void> {
    await this.$disconnect();
  }
}