Troubleshooting

Common NestJS-specific issues

Seeders running twice or not at all

Problem: Seeders run on every hot reload, or don't run on application bootstrap.

Cause: run-once tracking not enabled, or seeder modules not imported.

Solutions:

// runOnce: true is the default — seeders already in the history table are skipped
SeederModule.forRoot({ seeders: [UserSeeder, PostSeeder] })

// If runOnce is explicitly set to false, every boot re-runs all seeders
SeederModule.forRoot({ seeders: [UserSeeder, PostSeeder], runOnce: false }) // ← remove this

// If dropSchema: true is set on TypeORM, the history table is dropped every restart,
// so all seeders always run — this is usually intentional in development

If seeders are not running at all, confirm SeederModule is imported and that the enabled option (if set) evaluates to true.

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Still stuck?

• Check Getting started for module setup
• See Seed scripts for running seeders manually
• Review TypeORM troubleshooting for non-NestJS issues
• Open an issue on GitHub