# Editing your project If you want to add more data models, endpoints, or change the existing configuration of your project, use the following command to edit it: ``` alpio projects edit ``` You will be able to edit its configuration, through the same process you used in the [Configuring your project](https://docs.alpio.cloud/alpio/quickstart-your-first-project/configuring-your-project) step. Once you are done, you can choose to immediately deploy your modifications, or deploy later using the following command: ``` alpio projects deploy ``` ## Querying nested elements When we defined our Planet and Galaxy models, we [added a link between them](https://docs.alpio.cloud/alpio/configuring-your-project#adding-relationships-between-data-models). More specifically, we added a `galaxy` property on our Planet model, which is a reference to a planet's parent galaxy. Let's say we now want to retrieve a planet and its parent Galaxy in the same request. We can add an `include_galaxy` query parameter to the `getPlanet` operation, which retrieves a single Planet by id. ```json { "operationId": "getPlanet", "parameters": [ { "name": "include_galaxy", "type": "boolean", "in": "query" } ], "responses": { ... } } ``` {% hint style="info" %} "Include" parameters are special parameters, designed to include related objects in a response. They must follow the format: `include_property` where "property" is the name of a property explicitly listed on your model. This property should be a reference to another existing model. {% endhint %} Let's now try to retrieve planet Neptune which [we created earlier](https://docs.alpio.cloud/alpio/using-your-project#creating-a-planet) and its parent galaxy, using its id. If you can't find it anymore, just make a quick [query to retrieve the list of planets](https://docs.alpio.cloud/alpio/using-your-project#listing-galaxies-and-planets). ```bash curl 'https://YOUR_PROJECT_URL/planets/PLANET_ID?include_galaxy=true' \ --request GET \ --header 'x-api-key: YOUR_API_KEY' ``` You should see the following result: ```json { "id":"PLANET_ID" "mass":1024 "name":"Neptune", "habitable":false, "atmosphere":[], "discovered_at":"1846-09-23T00:00:00.000Z", "galaxyId":"GALAXY_ID", "galaxy":{ "id":"GALAXY_ID", "name":"Milky Way" } } ``` Let's say we now want to do retrieve a galaxy, and all its planets in a single query. We could try to do the same thing we did previously, and add a `include_planets` parameter to our API `getGalaxy` operation's configuration. But remember, we said that include parameters only work for a relationship if the related element is declared as property on the origin mode, so we first need to explicitly declare a `planets` property on our Galaxy model. Let's run first: ```bash alpio projects edit ``` Then, let's add the planets property on the Galaxy model: ```json { "Galaxy": { "properties": { // previous properties "planets": { "type": "array", "items": { "type": "reference", "reference": "Planet" } } } } } ``` We can now add our `include_planets` query parameter on our `getGalaxy` operation: ```json5 { "operationId": "getGalaxy", "parameters": [ { "name": "include_planets", "type": "boolean", "in": "query" } ], "responses": { ... } } ``` Once you have saved these changes and deployed a new version of your project, we can try to make our query using the Milky Way's `id`: ```bash curl 'https://YOUR_PROJECT_URL/planets/GALAXY_ID?include_planets=true' \ --request GET \ --header 'x-api-key: YOUR_API_KEY' ``` This should return the following result: ```json { "id":"7a99ea83-e427-42c0-9949-8cb50be8deed", "name":"Milky Way", "planets":[ { "id":"b4085b58-7530-4886-ab92-d2a80adf3e6e", "mass":1024,"name":"Neptune", "habitable":false, "atmosphere":[], "discovered_at":"1846-09-23T00:00:00.000Z", "galaxyId":"7a99ea83-e427-42c0-9949-8cb50be8deed" } ] } ``` We can retrieve a galaxy and all its related planets in one query. Victory! ## Linking an entity to another one When we created planet Earth in our data model, we somehow forgot to link it to a galaxy. Now that we have seen how to query related entities, let's say how we can link two related entities together. We know that our Planet model features a `galaxy` property, which is an object reference to a Galaxy model. If we could pass an object containing an existing Galaxy's id in a request to update a Planet, we could link the two together. Let's edit our API model, and add a `PATCH` request under the path `/planets/:id` ```json { "paths": { // ... other paths "/planets": { "paths": { "/:id": { "methods": { // ... other methods previously defined "patch": { "operationId": "updatePlanet", "body": { "type": "reference", "reference": "Planet" }, "responses": { "200": { "type": "reference", "reference": "Planet", "description": "A successful response" } } } } } } } } } ``` Once you have saved and deployed, we'll be able to try our new method. Let's finally link planet Earth to the Milky Way: 
curl 'https://YOUR_PROJECT_URL/planets/PLANET_ID' \
--request PATCH \
--header 'x-api-key: YOUR_API_KEY' \
--header 'content-type: application/json' \
--data '{"galaxy": {"id": "GALAXY_ID"}}'
You should see the following result: ```json5 { "id":"PLANET_ID", "mass":5972, "name":"Earth", "habitable":true, "atmosphere":[], "discovered_at":"0001-01-01T00:00:00.000Z", "galaxyId":"GALAXY_ID" // This should now be set to the Milky Way's id } ``` We can finally make a request to retrieve the Miky Way and its linked planets: ```bash curl 'https://YOUR_PROJECT_URL/galaxies/GALAXY_ID?include_planets=true' \ --request GET \ --header 'x-api-key: YOUR_API_KEY' ``` You should see the following result: ```json { "id":"GALAXY_ID", "name":"Milky Way", "planets":[ { "id":"NEPTUNE_ID", "mass":1024, "name":"Neptune", "habitable":false, "atmosphere":[], "discovered_at":"1846-09-23T00:00:00.000Z", "galaxyId":"GALAXY_ID" }, { "id":"EARTH_ID", "mass":5972, "name":"Earth", "habitable":true, "atmosphere":[], "discovered_at":"0001-01-01T00:00:00.000Z", "galaxyId":"GALAXY_ID" } ] } ``` [^1]: Replace this with your project's URL [^2]: Replace this your API key