In order to set up GraphQL access to the database we need to update the schema:
using extension graphql;
module default {
type Person {
required property first_name -> str;
property last_name -> str;
property name :=
.first_name ++ ' ' ++ .last_name
IF EXISTS .last_name
ELSE .first_name;
}
type Movie {
required property title -> str;
# the year of release
property year -> int64;
required link director -> Person;
multi link actors -> Person;
}
};After the schema is updated, we use the migration tools to create a new migration and apply it:
$
edgedb -I tutorial create-migrationdid you create extension 'graphql'? [y,n,l,c,b,s,q,?] y Created ./dbschema/migrations/00004.edgeql, id: m12exapirxxcs227zb2sruf7byvupbt6klkyl5ib6nyklyg3xo5s7a
$
edgedb -I tutorial migrateApplied m12exapirxxcs227zb2sruf7byvupbt6klkyl5ib6nyklyg3xo5s7a (00004.edgeql)
This will expose GraphQL API via http.
Each EdgeDB instance will be exposed on its corresponding port. Look
at $HOME/.edgedb/credentials/tutorial.json file to find out the
port for the tutorial instance. For the purpose of the example, we’ll
pretend that our tutorial instance is using port 5656 and so the
GraphQL API is exposed on:
http://127.0.0.1:5656/db/edgedb/graphql. Pointing your browser to
http://127.0.0.1:5656/db/edgedb/graphql/explore will bring up a
GraphiQL interface to EdgeDB. This interface can be used to try out
queries and explore the GraphQL capabilities.
Let’s look at a basic Movie query:
{
Movie {
title
year
}
}Which results in:
{
"data": {
"Movie": [
{
"title": "Blade Runner 2049",
"year": 2017
},
{
"title": "Dune",
"year": null
}
]
}
}It’s possible to apply a filter to
get a specific Movie:
{
Movie(filter: {title: {eq: "Dune"}}) {
title
year
director { name }
actors { name }
}
}Which results in:
{
"data": {
"Movie": [
{
"title": "Dune",
"year": null,
"director": {
"name": "Denis Villeneuve"
},
"actors": [
{
"name": "Jason Momoa"
},
{
"name": "Zendaya"
},
{
"name": "Oscar Isaac"
}
]
}
]
}
}If we wanted to provide some customized information, like which
Movie a Person acted in without altering the existing types,
we could do that by creating an alias
instead. Let’s add that alias to the schema:
using extension graphql;
module default {
type Person {
required property first_name -> str;
property last_name -> str;
property name :=
.first_name ++ ' ' ++ .last_name
IF EXISTS .last_name
ELSE .first_name;
}
type Movie {
required property title -> str;
# the year of release
property year -> int64;
required link director -> Person;
multi link actors -> Person;
}
alias PersonAlias := Person {
acted_in := Person.<actors[IS Movie]
};
};Then we create a new migration and apply it:
$
edgedb -I tutorial create-migrationdid you create alias 'default::PersonAlias'? [y,n,l,c,b,s,q,?] y Created ./dbschema/migrations/00005.edgeql, id: m1td3ogdzqhztdaivw5bem4sjl3otxfx6fmqngzayymqfwtwbolroa
$
edgedb -I tutorial migrateApplied m1td3ogdzqhztdaivw5bem4sjl3otxfx6fmqngzayymqfwtwbolroa (00005.edgeql)
Now, after reloading the GraphiQL page, we will be able to access the
PersonAlias:
{
PersonAlias(order: {first_name: {dir: ASC}}) {
name
acted_in { title }
}
}Which results in:
{
"data": {
"PersonAlias": [
{
"name": "Ana de Armas",
"acted_in": [
{
"title": "Blade Runner 2049"
}
]
},
{
"name": "Denis Villeneuve",
"acted_in": []
},
{
"name": "Harrison Ford",
"acted_in": [
{
"title": "Blade Runner 2049"
}
]
},
{
"name": "Jason Momoa",
"acted_in": [
{
"title": "Dune"
}
]
},
{
"name": "Oscar Isaac",
"acted_in": [
{
"title": "Dune"
}
]
},
{
"name": "Ryan Gosling",
"acted_in": [
{
"title": "Blade Runner 2049"
}
]
},
{
"name": "Zendaya",
"acted_in": [
{
"title": "Dune"
}
]
}
]
}
}