Delete documents using query syntax with the Solr API

Goal

How can I delete documents based on a query (e.g., matching a field value) rather than specifying individual document IDs?

Environment

Fusion 4.2.6 and Fusion 5.x (Self-Hosted deployments)

Guide

Fusion does not provide a dedicated Fusion API endpoint for deleting documents using query syntax. However, because Fusion uses Solr as the underlying search engine, you can use Solr’s native delete-by-query capability to achieve this.

Use the following curl command to delete documents that match a specified query from a Solr collection:

curl -X POST "http://<SOLR_HOST>:8983/solr/<COLLECTION_NAME>/update?commit=true" \
  -H "Content-Type: text/json" \
  --data-binary '{"delete": {"query": "<QUERY_SYNTAX>"}}'

Example

To delete all documents where the title field contains a value that starts with "foo":

curl -X POST "http://localhost:8983/solr/my_collection/update?commit=true" \
  -H "Content-Type: text/json" \
  --data-binary '{"delete": {"query": "title:*foo*"}}'

This command sends a JSON payload to the Solr update endpoint for the specified collection. The commit=true parameter ensures that the deletion is immediately committed.

Notes

• This operation directly accesses the Solr endpoint, so you must know the Solr host and collection name.

• Query syntax follows Solr's Lucene-style query parser.

• Ensure appropriate authentication or network access is configured if Solr is secured or behind a firewall.

• Deleting large volumes of documents can impact system performance. Use with caution.

If a Fusion-native endpoint for query-based deletions becomes available in future releases, this article will be updated.