# Data Transfer Object (DTO)

DTOs are classes with a special `@Result` decorator that allow you to separate the module and query results, and you can also use validators and transformers with them.

Any class can act as a DTO. It is enough to use `@Result` correctly

```typescript
// Module class
@Table()
@NamedTable('users')
class Users extends Module {
    
    @AutoIncrementId()
    public id!: number;
    
    @Column({ type: ColumnType.VARCHAR(64) })
    public first_name!: string;

    @Column({ type: ColumnType.VARCHAR(64) })
    public last_name!: string;
    
}

// DTO
class UserDTO {
    
    @Result() // If left blank, it will take the name of the field
    public id!: number;
    
    @Result('first_name')
    public firstName!: string;
    
    @Result('last_name')
    public lastName!: string;
    
}
```

Now you can use it either in Repository as the second argument, or directly in QueryBuilder

**Repository example**

```typescript
const usersRepository = new Repository(Users, UserDTO);
const user : UserDTO | null = await usersRepository.findOne({ first_name: 'Michael' }, { order: { id: 'DESC' } })
```

**QueryBuilder example**

```typescript
const results : UserDTO[] = new QueryBuilder()
    .setTable(Users)
    .setType(QueryType.SELECT)
    .setWhere(
        new WhereBuilder()
            .equalAnd("first_name", "Alexey")
    )
    .build()
    .get(UserDTO)
```

### [Next >](Validators.md)