I have been looking for different solutions that can help how to seed data inside database using a helper function without using any third part package.
After struggling with different methods and solutions then I come up with this solutions. It works fine without any third part package.
Let's dive deep into code
Assuming you generated your application with NestJS CLI 9
Your App module will look like below
app.module.ts
import { Module } from '@nestjs/common';
import { TypeOrmModule } from '@nestjs/typeorm';
@Module({
imports: [
TypeOrmModule.forRoot({
type: 'mysql',
host: 'localhost',
port: 3306,
username: 'root',
password: 'root',
database: 'test',
entities: ['dist/**/*.entity{.ts,.js}'],
synchronize: true,
autoLoadEntities: true,
}),
],
})
export class AppModule {}
Then create a seeder helper function like this below, Feel free to add more data as you want.
seed-data.ts
import { DataSource, In } from 'typeorm';
import { Permission } from '../../modules/permissions/entities/permission.entity';
import { Role } from '../../modules/permissions/entities/role.entity';
import { Auth } from '../../modules/users/entities/auth.entity';
import { PERMISSIONS_LIST } from './data/permissions.seeders';
import { ROLE_LIST } from './data/roles.seeders';
export async function seedData(dataSource: DataSource): Promise<void> {
const permissionRepository = dataSource.getRepository(Permission);
const roleRepository = dataSource.getRepository(Role);
const permissionsList = PERMISSIONS_LIST;
for (const permission of permissionsList) {
let _permission = permissionRepository.create(
permission as unknown as Permission,
);
await permissionRepository.save(_permission);
}
const rolesList = ROLE_LIST;
for (const role of rolesList) {
let _permissions = await permissionRepository.findBy({
id: In(role.permissions),
});
let _roleItem = {
name: role.name,
guard: role.guard,
code: role.code,
};
let _role = roleRepository.create({
..._roleItem,
permissions: _permissions,
});
await roleRepository.save(_role);
}
}
Note that ROLE_LIST and PERMISSION_LIST are sample data in an array format like
data.ts
import { GuardType } from "src/modules/permissions/entities/guard-type.enum";
export const ROLE_LIST = [
{
name: "admin",
guard: GuardType.ADMIN,
code: "admin",
permissions: [1, 2]
},
{
name: "user",
guard: GuardType.USER,
code: "user",
permissions: [2]
},
{
name: "test",
guard: GuardType.TEST,
code: "test",
permissions: [2]
}
];
Then write a helper function to boostrap your app using NestFactory function like below
seed.helper.ts
import { DataSource } from 'typeorm';
import { seedData } from './seed-data';
import { AppModule } from '../../app.module';
import { NestFactory } from '@nestjs/core';
async function runSeeder() {
const app = await NestFactory.create(AppModule);
const dataSource = app.get(DataSource);
await seedData(dataSource);
await app.close();
}
runSeeder();
Then final add the command to package.json file so that you can execute a runSeeder function inside package.json.
package.json
"scripts": {
"build": "nest build",
...
"data:sync": "ts-node -r tsconfig-paths/register ./src/seeders/seed.helper.ts"
Now everything is now set just run npm run data:sync now data should be populated in the database.
Feel free to leave a comment in this post below.
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