Native Queries
Introduction
Native Queries allow you to run custom SQL queries on your BigQuery database. These allow you to run queries that are not supported by Hasura's DDN GraphQL API by default.
Structure
A Native Query is a single SQL statement that returns results and can take arguments. The SQL structure of a Native Query is specified in the Native Operation syntax page.
Create a Native Query
To create a new Native Query, create a new SQL file inside the connector configuration directory, then use the ddn
CLI
to add it to the connector configuration. For example:
-
Create a new directory structure under the connector configuration:
mkdir -p my_subgraph/connector/bigquery-connector/native_operations/queries/
-
Create a new SQL file
my_subgraph/connector/bigquery-connector/native_operations/queries/artist_by_name_between.sql
with the following content:SELECT *
FROM "Artist"
WHERE "Name" LIKE :name
AND "ArtistId" > :lower_bound
AND "ArtistId" < :upper_bound -
Create a new entry in the connector configuration:
NOTE: The
operation-path
provided should be relative to the configuration directory. It means that for the below case, the SQL file is expected to be present at<ddn-project-root>/my_subgraph/connector/bigquery-connector/native-operations/queries/artist_by_name_between.sql
ddn connector plugin --connector my_subgraph/connector/bigquery-connector/connector.yaml -- \
native-queries create --operation-path native_operations/queries/artist_by_name_between.sql --name artist_by_name_between -
If your data connector is running, run the following command to update your metadata to track the new native query:
ddn connector-link update bigquery_connector --add-all-resources
If you get a
connection refused
error, it means that your data connector is not running. You can either start the data connector and try again, or, run the following commands to update your metadata to track the new native query:# start the connector and introspect your DB
ddn connector introspect bigquery_connector
# update your metadata to track the new native query
ddn model add bigquery_connector "artist_by_name_between"
Updating a Native Query
A Native Query can be updated with the create
command and setting the --overwrite
option. For example:
ddn connector plugin --connector my_subgraph/connector/bigquery_connector/connector.yaml -- \
native-queries create --name artist_by_name_between --operation-path native_operations/queries/artist_by_name_between.sql --overwrite
Usage
With the example above, you can then use the query in your GraphQL API like this:
query {
artist_by_name_between(args: {name: "Black", lower_bound: 10, upper_bound: 50}) {
ArtistId
Name
}
}