Cosmos DB - Deleting a document

How can I delete an individual record from Cosmos DB?

I can select using SQL syntax:

SELECT *
FROM collection1
WHERE (collection1._ts > 0)

And sure enough all documents (analogous to rows?) are returned

However this doesn't work when I attempt to delete

DELETE
FROM collection1
WHERE (collection1._ts > 0)

How do I achieve that?

The DocumentDB API's SQL is specifically for querying. That is, it only provides SELECT, not UPDATE or DELETE.

Those operations are fully supported, but require REST (or SDK) calls. For example, with .net, you'd call DeleteDocumentAsync() or ReplaceDocumentAsync(), and in node.js, this would be a call to deleteDocument() or replaceDocument().

In your particular scenario, you could run your SELECT to identify documents for deletion, then make "delete" calls, one per document (or, for efficiency and transactionality, pass an array of documents to delete, into a stored procedure).

The easiest way is probably by using Azure Storage Explorer. After connecting you can drill down to a container of choice, select a document and then delete it. You can find additional tools for Cosmos DB on https://gotcosmos.com/tools.

Another option to consider is the time to live (TTL). You can turn this on for a collection and then set an expiration for the documents. The documents will be cleaned up automatically for you as they expire.