Merge pull request #1475 from teleginzhenya/feature/mongoose-prop-ref-example

Mongoose @prop decorator ref example

Author: kamilmysliwiec

CONTRIBUTING.md

@@ -169,10 +169,10 @@ Footer should contain a [closing reference to an issue](https://help.github.com/
 Samples: (even more [samples](https://github.com/nestjs/nest/commits/master))
 
 ```
-docs(changelog) update change log to beta.5
+docs(changelog): update change log to beta.5
 ```
 ```
-bugfix(@nestjs/core) need to depend on latest rxjs and zone.js
+bugfix(@nestjs/core): need to depend on latest rxjs and zone.js
 
 The version in our package.json gets copied to the one we publish, and users need the latest of these.
 ```

content/techniques/mongo.md

@@ -72,6 +72,21 @@ Alternatively, the `@Prop()` decorator accepts an options object argument ([read
 name: string;
 ```
 
+In case you want to specify relation to another model, later for populating, you can use `@Prop()` decorator as well. For example, if `Cat` has `Owner` which is stored in a different collection called `owners`, the property should have type and ref. For example:
+
+```typescript
+import { Types } from 'mongoose';
+import { Owner } from '../owners/schemas/owner.schema';
+
+@Prop({ type: Types.ObjectId, ref: Owner.name })
+owner: Owner;
+```
+
+In case there are multiple owners, your property configuration should look as follows:
+
+```typescript
+@Prop({ type: [Types.ObjectId], ref: Owner.name })
+owner: Owner[];
 Finally, the **raw** schema definition can also be passed to the decorator. This is useful when, for example, a property represents a nested object which is not defined as a class. For this, use the `raw()` function from the `@nestjs/mongoose` package, as follows:
 
 ```typescript