I have a very simple schema structure in my mobile app:
export const DepositSchema = {
name: "Deposit",
properties: {
uuid: "string",
payments: "Payment[]",
},
primaryKey: "uuid",
};
export const PaymentSchema = {
name: Instance.Payment,
properties: {
payment_amount: "string",
payment_method: "string",
deposit: {
type: "linkingObjects",
objectType: "Deposit",
property: "payments",
},
},
primaryKey: "uuid",
};
So means that every deposit can have zero, one or few payments (it can be paid partially), but one payment should be assigned only to one deposit
I put Payment objects to Realm database as below:
database.manager.write(() => {
if (payment.deposit_uuid) {
deposit = database.manager.objectForPrimaryKey("Deposit", payment.deposit_uuid);
}
const createdDbPayment = database.manager.create(
Instance.Payment,
{
...payment,
status: STATUS_TO_IGNORE,
},
Realm.UpdateMode.Modified,
);
if (deposit && createdDbPayment && deposit.payments.filtered("uuid == $0", payment.uuid).length == 0) {
deposit.payments.push(createdDbPayment);
}
});
Meanwhile, when i try to log payment object gotten from Realm Database it looks that instead of one deposit assigned to this payment, I got array of deposits. (ofc with only one object but it's very annoying)
The question is: Is there a way to connect this schema to present One2Many (not many2many) relationship?
I would like to achieve:
payment.deposit.uuid
instead of payment.deposit[0]?.uuid
Thanks for help
I would like to achieve: payment.deposit.uuid instead of payment.deposit[0]?.uuid
Whenever LinkingObjects are used, they allow "automatic" navigation back to the parent object - however, they also create a many-many relationship by their nature.
That's why it's LinkingObjects
(plural) not LinkingObject
.
If there is only ever one to link back to, then your code will work with the index 0 being required to reference to the first element
payment.deposit[0]?.uuid
The benefit of LinkingObjects is the backlink is created for you (it's more of a calculated property than a managed property). On the other hand it's not exactly what you want.
So you'll need to create the backlink manually - and in some cases it makes more sense but you loose the 'automatic' relationship. Using pseudo-code
export const DepositSchema = {
name: "Deposit",
properties: {
payments: "Payment[]"
export const PaymentSchema = {
name: Payment,
properties: {
parent_deposit: "Deposit"
I would suggest adding a "addPayment" function to add a payment to the Deposit. When a payment is passed to the Deposit property, the parent Deposit will add its reference to the payment and then add it to the Payments List.
That will create a forward relationship from Deposits to multiple Payments and then a single backward relationship from Payment back to its parent Deposit.
Then the graph can be transversed in both directions.