Schema/Metadata API Reference: Custom Functions¶
Table of contents
Track/untrack a custom SQL function in the Hasura GraphQL engine.
Only tracked custom functions are available for querying/mutating/subscribing data over the GraphQL API.
track_function¶
track_function is used to add a custom SQL function to the GraphQL schema.
Also refer a note here.
Add an SQL function search_articles:
POST /v1/query HTTP/1.1
Content-Type: application/json
X-Hasura-Role: admin
{
"type": "track_function",
"args": {
"schema": "public",
"name": "search_articles"
}
}
track_function v2¶
Version 2 of track_function is used to add a custom SQL function to the GraphQL schema with configuration.
Also refer a note here.
Add an SQL function called search_articles with a Hasura session argument.
POST /v1/query HTTP/1.1
Content-Type: application/json
X-Hasura-Role: admin
{
"type": "track_function",
"version": 2,
"args": {
"function": {
"schema": "public",
"name": "search_articles"
},
"configuration": {
"session_argument": "hasura_session"
}
}
}
Args syntax¶
| Key | Required | Schema | Description |
|---|---|---|---|
| function | true | FunctionName | Name of the SQL function |
| configuration | false | Function Configuration | Configuration for the SQL function |
Function Configuration¶
| Key | Required | Schema | Description |
|---|---|---|---|
| session_argument | false | String | Function argument which accepts session info JSON |
Note
Currently, only functions which satisfy the following constraints can be exposed over the GraphQL API (terminology from Postgres docs):
- Function behaviour: ONLY
STABLEorIMMUTABLE - Return type: MUST be
SETOF <table-name> - Argument modes: ONLY
IN
untrack_function¶
untrack_function is used to remove a SQL function from the GraphQL schema.
Remove an SQL function search_articles:
POST /v1/query HTTP/1.1
Content-Type: application/json
X-Hasura-Role: admin
{
"type": "untrack_function",
"args": {
"schema": "public",
"name": "search_articles"
}
}
Args syntax¶
| Key | Required | Schema | Description |
|---|---|---|---|
| table | true | FunctionName | Name of the SQL function |
