How to save entity with ManyToOne with nullable: false set?

[draoncc]

Issue type:

[x] question
[ ] bug report
[ ] feature request
[ ] documentation issue

Database system/driver:

[ ] cordova
[ ] mongodb
[ ] mssql
[ ] mysql / mariadb
[ ] oracle
[x] postgres
[ ] sqlite
[ ] sqljs
[ ] react-native
[ ] expo

TypeORM version:

[x] latest
[ ] @next
[ ] 0.x.x (or put your version here)

Steps to reproduce or a small repository showing the problem:

I'm terribly tired so apologies if the answer is obvious, and I'm just blind and not seeing it.

Assuming the following two entities:

@Entity()
export class Parent {
  @PrimaryGeneratedColumn()
  id!: number

  @OneToMany(type => Child, child => child.parent)
  children!: Child[]
}

@Entity()
export class Child {
  @PrimaryGeneratedColumn()
  id!: number

  @ManyToOne(type => Parent, parent => parent.children, { nullable: false })
  parent!: Parent
}

When doing entityManager.insert(Child, {}), naturally the error null value in column \"parentId\" violates not-null constraint is thrown. When trying to do entityManager.insert(Child, { parentId: 1 }), the same error is thrown though.

So how do I create and save new Childs with the above model?

[vlapo]

Your Child entity do not have defined parentId column in entity class. I am getting error in IDE

Object literal may only specify known properties, and 'parentId' does not exist in type 'QueryPartialEntity<Child> | QueryPartialEntity<Child>[]'. [2345]

So typeorm will ignore this property value during query build. Of course typeorm know about this join column but entity argument of insert is QueryPartialEntity<Child>|(QueryPartialEntity<Child>[]) so does not expect parentId property.

There are two options:

1. Define additional parentId column in Child class.

@Entity()
export class Child {
    @PrimaryGeneratedColumn()
    id!: number;

    @Column()
    parentId: number;

    @ManyToOne(type => Parent, parent => parent.children, { nullable: false })
    parent!: Parent;
}

2. Use little trick and call insert method like this:

await entityManager.insert(Child, { parent: { id: 1 } as Parent });