@OneToMany w/ cascade: am I just setting this up wrong?

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

TypeORM version:

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

I’m trying to set up @OneToMany relationships with cascade. The child objects get inserted into the database, but the foreign key value (gather_id) is null. I’ve been struggling to figure out whether I have this set up correctly.

// Parent class
@Entity('gathers')
export class Gather {

    constructor(data?: GatherDataType) {
        if (data) {
            this.appVersion = data.appVersion;
            this.createPacketObjectsFromRawHex(data.rawData);
        }
    }

    @PrimaryGeneratedColumn()
    id: number;

    @Column({
        name: 'app_version',
    })
    appVersion: string;

    @OneToMany(type => Device, device => device.id, {
        cascade: true,
        onDelete: 'CASCADE',
    })
    devices: Device[];

    createPacketObjectsFromRawHex = (rawData: RawDataType) => {

        const packetObjects = {};

        Object.entries(rawData).forEach(d => {
            const syncTime = +d[0];
            const rawHex = d[1];
            const typeHex = rawHex.substr(8, 4);
            let packetObj = {};

            switch (typeHex) {
                // simplified... removed most cases
                case PacketType.Device:
                    packetObj = new Device(rawHex, syncTime);
                    break;
            }

            if (!packetObjects[typeHex]) {
                packetObjects[typeHex] = [];
            }

            packetObjects[typeHex].push(packetObj);
        });

        this.devices = packetObjects[PacketType.Device];
    }
}

// Child class
@Entity('devices')
export class Device extends BatteryDeviceBase {

    constructor(rawHex?: string, syncTime?: number) {
        super(rawHex, syncTime);
    }

    @ManyToOne(type => Gather, gather => gather.devices)
    @JoinColumn({ name: 'gather_id' })
    gather: Gather;

}

// How I'm calling this, passing in a `gatherData` JSON object...
const gather = new Gather(gatherData);
await connection.manager.save(gather);

All the inserts happen, i.e., a gather row and device rows, but device.gather_id is null.

I tried setting nullable: false on the @ManyToOne column but that just results in an INSERT error, as one would expect.

I tried cascade: true on the @ManyToOne but that resulted in no inserts at all.

I also tried calling the createPacketObjectsFromRawHex method after creating the Gather object (i.e., not in the constructor), but that didn’t make a difference.

[vedranjukic]

I’m facing the same issue

[CemYil03]

Let’s use an example for a one to many relation: one User has many Posts. In the User class you would find: @OneToMany(() => Post, (post: Post) => post.user, { cascade: true }). { cascade: true } gives the direction to resolve and persist nested relations when you use thesave method on repositories, nothing else.

usersRepository.save({
   ...userFields,
   posts: [        // <-- { cascade: true } triggers that this gets detected and resolved to sql insert statements
      { ...postFieldsForFirstPost },
      { ...postFieldsForSecondPost }
   ]
});