TypeOrm findOne throws 'Argument passed in must be a single String of 12 bytes or a string of 24 hex characters'

Question

Hi I'm using NestJs with TypeOrm and currently connected to a MongoDB (but I want to be independent because most customers use MSSQL and Postgres databases).

Basically I want to store a key/value pair to the database. Both are of type String. This is the mapping entity holding the pair

@Entity()
export class Mapping extends BaseEntity {
  @PrimaryColumn()
  key: string;

  @Column()
  value: string;
}

The repository is currently empty

@EntityRepository(Mapping)
export class MappingsRepository extends Repository<Mapping> {}

In my service file I try to find a value by its key

  public async getValueByKey(key: string): Promise<string> {
    const mapping: Mapping = await this.mappingsRepository.findOne(key);

    if (!mapping) {
      throw new NotFoundException(`Key ${key} does not exist`);
    }

    return mapping.value;
  }

Unfortunately the findOne function always throws this error when passing in a key

Argument passed in must be a single String of 12 bytes or a string of 24 hex characters

How can I fix this so that I can pass in any keys of type String? The parameter key is defined, I tried it with dummy values like f or ffsdagsdgfdg

Answer 1

Can you try

await this.mappingsRepository.findOne({key});

My guess it that typeorm doesn't understand primary key other than id