Remote schema relationships¶
Table of contents
Introduction¶
Remote schema relationships extend the concept of joining data across tables, to joining across tables and remote data sources. Once you create relationships between types from your database and types created from APIs, you can then “join” them by running GraphQL queries.
These APIs can be custom GraphQL servers you write, third party SaaS APIs, or even other Hasura instances.
Because Hasura is meant to be a GraphQL server that you can expose directly to your apps, Hasura also handles security and authorization while providing remote joins.
Note
To see example use cases, check out this blog post.
Supported from
Remote schema relationships are supported from versions v.1.3.0
and above.
Create remote schema relationships¶
Step 1: Open the remote relationship section¶
- From your table, go to the
Relationships
tab. - Click the
Add a remote relationship
button.
Step 2: Define the relationship¶
The following fields can be defined for a remote schema relationship:
- Name: Define a name for the relationship.
- Remote Schema: Select a remote schema among all the ones you’ve created.
- Configuration: Set up the join configuration, to inject values as input arguments of the remote schema field.
- From column: Input injected from table column values.
- From static value: Input injected from a static value of your choice.
For this example, we assume that our schema has a users
table with the fields name
and auth0_id
.
You can add a remote schema relationship by adding it to the tables.yaml
in the metadata
directory:
- table:
schema: public
name: users
remote_relationships:
- definition:
remote_field:
auth0profile:
arguments:
id: $auth0_id
hasura_fields:
- auth0_id
remote_schema: auth0
name: auth0
Apply the metadata by running:
hasura metadata apply
You can add a remote schema relationship by using the create_remote_relationship metadata API:
POST /v1/query HTTP/1.1
Content-Type: application/json
X-Hasura-Role: admin
{
"type": "create_remote_relationship",
"args": {
"name": "auth0_profile",
"table": "users",
"hasura_fields": [
"auth0_id"
],
"remote_schema": "auth0",
"remote_field": {
"auth0": {
"arguments": {
"auth0_id": "$auth0_id"
}
}
}
}
}
In this example, we’ve added a remote schema which is a wrapper around Auth0’s REST API (see example here).
- We name the relationship
auth0_profile
. - We select the
auth0
schema that we’ve added. - We set up the config to join the
auth0_id
input argument of our remote schema field to theauth0_id
column of this table (in this case, theusers
table).
Step 3: Explore with GraphiQL¶
In the GraphiQL tab, test out your remote schema relationship.
query {
users {
name
auth0_profile {
nickname
email
last_login
}
}
}