108 lines
2.5 KiB
Plaintext
108 lines
2.5 KiB
Plaintext
export const metadata = {
|
|
title: `${pageNumber} Common Data Model Definitions`,
|
|
}
|
|
|
|
# {metadata.title}
|
|
|
|
In this chapter, you'll learn where to find resources on common data model definitions related to field's column types, relations, and indices.
|
|
|
|
## MikroORM Learning Resources
|
|
|
|
Refer to the following resources to learn about common definitions:
|
|
|
|
1. [Field column types](https://mikro-orm.io/docs/defining-entities).
|
|
2. [Creating indices](https://mikro-orm.io/docs/defining-entities#indexes).
|
|
|
|
Refer to MikroORM's documentation for more details related to your use case.
|
|
|
|
---
|
|
|
|
## Relations Between Data Models
|
|
|
|
You can build relations between data models in the same module using foreign keys.
|
|
|
|
Refer to [MikroORM's relations definitions](https://mikro-orm.io/docs/relationships) for more details.
|
|
|
|
<Note>
|
|
|
|
For building relationships between data models in different modules, refer to the [Module Relationships chapter](../../modules/module-relationships/page.mdx) instead.
|
|
|
|
</Note>
|
|
|
|
---
|
|
|
|
## Example Data Model
|
|
|
|
The following example showcase a data model with common definitions:
|
|
|
|
```ts
|
|
import {
|
|
BeforeCreate,
|
|
Entity,
|
|
Enum,
|
|
OneToOne,
|
|
PrimaryKey,
|
|
Property,
|
|
} from "@mikro-orm/core"
|
|
import {
|
|
createPsqlIndexStatementHelper,
|
|
generateEntityId,
|
|
} from "@medusajs/utils"
|
|
import ProductVariant from "./product-variant"
|
|
|
|
export enum MediaType {
|
|
MAIN = "main",
|
|
PREVIEW = "preview"
|
|
}
|
|
|
|
const VariantIdIndex = createPsqlIndexStatementHelper({
|
|
name: "IDX_product_media_variant_id",
|
|
tableName: "product_media",
|
|
columns: "variant_id",
|
|
}).MikroORMIndex
|
|
|
|
@Entity()
|
|
export default class ProductMedia {
|
|
@PrimaryKey({ columnType: "text" })
|
|
id: string
|
|
|
|
@Property({ columnType: "text" })
|
|
name: string
|
|
|
|
@Enum({ items: ["main", "preview"] })
|
|
type: MediaType
|
|
|
|
@Property({ columnType: "text" })
|
|
file_key: string
|
|
|
|
@Property({ columnType: "text" })
|
|
mime_type: string
|
|
|
|
@VariantIdIndex()
|
|
@Property({ columnType: "text" })
|
|
variant_id: string
|
|
|
|
@OneToOne({
|
|
entity: ProductVariant,
|
|
onDelete: "cascade",
|
|
})
|
|
variant: ProductVariant
|
|
|
|
@BeforeCreate()
|
|
onCreate() {
|
|
this.id = generateEntityId(this.id, "promed")
|
|
}
|
|
|
|
@OnInit()
|
|
OnInit() {
|
|
this.id = generateEntityId(this.id, "promed")
|
|
}
|
|
}
|
|
```
|
|
|
|
In the example above:
|
|
|
|
- The `ProductMedia` data model has the columns `id`, `name`, `type`, `file_key`, `mime_type`, and `variant_id`.
|
|
- The data model has an index on the `variant_id` column.
|
|
- The data model has a one-to-one relation to the `ProductVariant` data model.
|