Delete or Replace Values in a Named Sub-Graph¶
Description¶
If you have created a named sub-graph, you can replace the entire sub-graph with a single API call, using the special #replaceGraph predicate. You can choose to just delete the sub-graph, or to delete the existing values and add new values in the same call.
In the call's payload, you first supply a triple that deletes the sub-graph, and then optionally add quads that contain the new graph values.
Note
You can also create a simple string alias for the graph name URI. See Using String Labels as Sub-Graph Aliases to learn more.
Syntax¶
URL: <cm-well-host>/_in
REST verb: POST
Mandatory parameters:
<> <cmwell://meta/sys#replaceGraph> <graph to delete/replace> <optional: quads to add>
Template:
curl -X POST "<cm-well-host>/_in?format=nquads" -H "Content-Type: text/plain" --data
'<> <cmwell://meta/sys#replaceGraph> <graph to replace>.
<quads to add>'
URL example: N/A
Curl example (REST API):
curl -X POST "<cm-well-host>/_in?format=nquads" -H "Content-Type: text/plain" --data-binary @curlInput.txt
File Contents¶
<> <cmwell://meta/sys#replaceGraph> <http://MyOntology/MovieGoers>.
<http://example.org/movies/ET> <http://MyOntology/Score> "10" <http://MyOntology/MovieGoers>.
<http://example.org/movies/GoneWithTheWind> <http://MyOntology/Score> "10" <http://MyOntology/MovieGoers>.
<http://example.org/movies/TheAvenger> <http://MyOntology/Score> "10" <http://MyOntology/MovieGoers>.
Special Parameters¶
| Parameter | Description | Values | Example |
|---|---|---|---|
| priority | If this flag appears in an update call, that call receives priority relative to non-priority calls. To use this flag, you must also pass the X-CM-WELL-TOKEN request header, with a token that grants access to the priority feature. This feature should be used with discretion so as not to flood the priority queue. | None |
Code Example¶
Call¶
curl -X POST "<cm-well-host>/_in?format=nquads" -H "Content-Type: text/plain" --data-binary @curlInput.txt
File Contents¶
<> <cmwell://meta/sys#replaceGraph> <http://MyOntology/MovieGoers>.
<http://example.org/movies/ET> <http://MyOntology/Score> "10" <http://MyOntology/MovieGoers>.
<http://example.org/movies/GoneWithTheWind> <http://MyOntology/Score> "10" <http://MyOntology/MovieGoers>.
<http://example.org/movies/TheAvenger> <http://MyOntology/Score> "10" <http://MyOntology/MovieGoers>.
Results¶
{"success":true}
Note
- If you want to replace values in a sub-graph, the best practice is to delete the old values and add the new values, all in the same call. This is because for every change made to an infoton, CM-Well retains a historical infoton version. If you split the operation into two calls, one to delete and one to add, the version after the delete is saved. This version is not interesting when tracing the infoton's history, and just takes up storage needlessly.
- If the sub-graph you requested to delete did not exist, you will receive a 422 ("Unprocessable Entity") return code.