Test case: any corpus. A query string _NULL * produces an SQL string that does not contain a corpus id.
SELECT
NULL AS coq_word_label_1,
COQ_WORD_2.Word AS coq_word_label_2,
COQ_CORPUS_1.ID AS coquery_invisible_corpus_id,
COQ_CORPUS_1.SourceId AS coquery_invisible_origin_id
FROM Corpus AS COQ_CORPUS_2
INNER JOIN Lexicon AS COQ_WORD_2 ON COQ_WORD_2.WordId = COQ_CORPUS_2.WordId
Test case: any corpus. A query string
_NULL *
produces an SQL string that does not contain a corpus id.