count(*) with ORDER BY returns empty result if no rows exist

[mmacfadden]

OrientDB Version: 3.0.26

Java Version: openJDK 11

OS: MacOS

Issue:

When performing a count with an ORDER BY. If no rows match, instead of getting a result with a count field set to 0, we get an empty result set. This is similar to #8280 and #8621 which I had previously reported.

Expected behavior

A count result of 0 should be returned.

Actual behavior

An empty result set is returned.

Steps to reproduce

Create the schema:

CREATE CLASS Test;
CREATE Property Test.id String;

Test 1 (Works)

SELECT count(*) as count FROM Test;

    "result": [
        {
            "@type": "d",
            "@version": 0,
            "count": 0,
            "@fieldTypes": "count=l"
        }
    ]

Test 2 (Doesn't Work)

SELECT count(*) as count FROM Test ORDER BY id ASC;

    "result": [
        
    ]

[luigidellaquila]

Hi @mmacfadden

this query does not make much sense semantically, but I think it's worth fixing anyway.
I'm pushing a fix now, it will be released with v 3.0.28

Thanks

[mmacfadden]

@luigidellaquila Thanks! You are correct, it is a little non-sensical. This came up because we were working with pagination and we have a utility that essentially takes your original query (that might have SKIP and LIMIT in it) and builds a second query that does the count to get the total result. The order by was coming from the original query!