Query multiple data sources in Fabric API for GraphQL
In Fabric API for GraphQL, you can expose many data sources through a single API item. This feature allows you to issue a single query that retrieves data across multiple data sources.
A multi-data source query is a sequence of queries that use perform operations against different data sources.
This functionality can enhance the performance of your applications by reducing the number of round trips between your application and the API for GraphQL.
Note
A multi-data source request fans out individual requests to data sources. You cannot create relationships across types that span multiple data sources. Additionally, there are no guarantees on the order the individual requests will execute.
Query example
The following example shows a query that spans across both the ContosoSales and the ContosoInventory data sources:
query {
customers (first: 1) {
items {
FirstName
LastName
}
}
inventories (first: 1) {
items {
Name
}
}
}
This request retrieves the first node from the customers query, which is derived from the ContosoSales data source, and the first node from the inventories query, which is derived from the ContosoInventory data source.
The output for the request is:
{
"data": {
"customers": {
"items": [
{
"FirstName": "Orlando",
"LastName": "Gee"
}
]
},
"inventories": {
"items": [
{
"Name": "AWC Logo Cap"
}
]
}
}
}
There are two parts to the output: The first section, "data" contains the output of the customers query. The second section, "inventories", contains the output of the inventories query.
This is how the query view looks like when executing this request:
