diff --git a/src/pages/[platform]/build-a-backend/data/data-modeling/relationships/index.mdx b/src/pages/[platform]/build-a-backend/data/data-modeling/relationships/index.mdx index 7e3934edfcf..ad8e2b07fa1 100644 --- a/src/pages/[platform]/build-a-backend/data/data-modeling/relationships/index.mdx +++ b/src/pages/[platform]/build-a-backend/data/data-modeling/relationships/index.mdx @@ -439,6 +439,29 @@ do { +### Handling orphaned foreign keys on parent record deletion in "Has Many" relationship + + + +```ts +// Get the IDs of the related members. +const { data: teamWithMembers } = await client.models.Team.get( + { id: teamId}, + { selectionSet: ["id", "members.*"] }, +); + +// Delete Team +await client.models.Team.delete({ id: teamWithMembers.id }); + +// Delete all members in parallel +await Promise.all( + teamWithMembers.members.map(member => + client.models.Member.delete({ id: member.id }) +)); +``` + + + ## Model a "one-to-one" relationship Create a one-to-one relationship between two models using the `hasOne()` and `belongsTo()` methods. In the example below, a **Customer** has a **Cart** and a *Cart* belongs to a **Customer**. @@ -794,6 +817,26 @@ val cart = Amplify.API.query( +### Handling orphaned foreign keys on parent record deletion in "Has One" relationship + + + +```ts +// Get the customer with their associated cart +const { data: customerWithCart } = await client.models.Customer.get( + { id: customerId }, + { selectionSet: ["id", "activeCart.*"] }, +); + +// Delete Cart if exists +await client.models.Cart.delete({ id: customerWithCart.activeCart.id }); + +// Delete the customer +await client.models.Customer.delete({ id: customerWithCart.id }); +``` + + + ## Model a "many-to-many" relationship In order to create a many-to-many relationship between two models, you have to create a model that serves as a "join table". This "join table" should contain two one-to-many relationships between the two related entities. For example, to model a **Post** that has many **Tags** and a **Tag** has many **Posts**, you'll need to create a new **PostTag** model that represents the relationship between these two entities.