Can I map entity field names to alias column names in typeorm?

Question

I am in the process of migrating from Rails to NestJs with TypeORM. For historical reasons, table names and column names in Rails are snaked_cased - I don't want to copy this nuisance to our NestJs/React side

Can I create entity fields in NestJS (typeorm) )called firstName but are mapped to a column named first_name in my DB?

My table

+-------------+--------------+----------------------------+
|                      system_users                       |
+-------------+--------------+----------------------------+
| id          | int(11)      | PRIMARY KEY AUTO_INCREMENT |
| first_name  | varchar(100) |                            |
| last_name   | varcahr(100) |                            |
+-------------+--------------+----------------------------+

My User Entity Class

import { Entity, Column, PrimaryGeneratedColumn } from 'typeorm';

@Entity({ name: 'system_users' })
export class User {
  @PrimaryGeneratedColumn()
  id: number;

  @Column({ length: 255 })
  first_name: string;  <-- I WANT THIS TO BE firstName (camelCased)

  @Column({ length: 255 })
  last_name: string;   <-- I WANT THIS TO BE lastName (camelCased)
}

Answer 1

I finally found what I was looking for in the documentation. The @Column attribute receives many properties, one of them is name which can define the column name associated with the field.

My updated entity:

@Entity({ name: 'system_users' })
export class User {
  @PrimaryGeneratedColumn()
  id: number;

  @Column({ length: 255, name: "first_name" })
  firstName: string; 

  @Column({ length: 255, name: "last_name" })
  lastName: string; 
}

Answer 2

If anyone else comes across this issue, know that TypeORM supports naming strategies .
And there is even a package for a snake case naming strategy