What is query for empty documents in N1QL?

SQL++
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1

Hi,
We observed in our database, few are created with empty data documents like {}. We dont know the reasons. But first we want to find how many records are in our database.

How to find the root cause also

2

During insert /upsert you might have created empty document or update with unset on single field document.

SELECT META(d).id  
FROM default AS d  
WHERE d = {};

Above query gives document keys (required primary index).

DELETE FROM default AS d
WHERE d = {};

Deletes them

3

Thank you for your response, is there any change those are create from couchbase mobile lite?

What do you mean of unset on single field?

4

Not sure about mobile lite. May be you can ask in Mobile topic

Example: After unset document will not have any fields. document will be empty and select gives “k01”

insert into default values ("k01",{"a":10});
update default USE KEYS "k01" unset a;
select META(d).id from default d  USE KEYS "k01" WHERE d = {};

The following query uses ix10 as covered index. Index contain only empty objects.

CREATE INDEX ix10 ON default(OBJECT_LENGTH(self))
WHERE OBJECT_LENGTH(self) = 0;

DELETE FROM default AS d
WHERE OBJECT_LENGTH(d) = 0;