# Introduction
## Use `flatEntityTranspilers.toScalarFlatEntity` in create action
handler
**Changes:**
- Modified
`BaseWorkspaceMigrationRunnerActionHandlerService.insertFlatEntitiesInRepository()`
to transform flat entities using `toScalarFlatEntity()` before database
insertion
**What it does:**
Strips out TypeORM relation objects and metadata-only properties,
ensuring only scalar values (primitives, IDs, dates) are inserted into
the database.
**Benefits:**
- **Type Safety:** Prevents accidental insertion of nested objects that
TypeORM can't persist
- **Consistency:** All 17+ create action handlers automatically benefit
from proper data transformation
- **Single Source of Truth:** Centralized logic for what constitutes a
database-insertable entity
- **Prevents Errors:** Uses entity configuration schema to ensure only
valid properties are included
## Usage
```ts
protected async insertFlatEntitiesInRepository({
flatEntities,
queryRunner,
}: {
queryRunner: QueryRunner;
flatEntities: MetadataFlatEntity<TMetadataName>[];
}) {
const metadataEntity =
ALL_METADATA_ENTITY_BY_METADATA_NAME[this.metadataName];
const repository = queryRunner.manager.getRepository(metadataEntity);
const scalarFlatEntities = flatEntities.map((flatEntity) =>
flatEntityTranspilers.toScalarFlatEntity({
flatEntity,
metadataName: this.metadataName,
}),
);
await repository.insert(scalarFlatEntities);
}
```
## Upcoming refactor
About to completely split the
`packages/twenty-server/src/engine/workspace-manager/workspace-migration/workspace-migration-runner/interfaces/workspace-migration-runner-action-handler-service.interface.ts`
into three dedicated boilerplate one for each action type `create`
`delete` `update` will provide a better interfacing and typing + will
allow not requiring the user to provide the metadata execute handler as
required
Paul Rastoin
f6b7ab2251