MariaDB not in issue

Certified Senior Developer

Hi, I wanted to return the rows from cases table which are not in mail poller. But for somereason the following query is not giving me the expected result. Can someone help what mistake I am doing here.

SELECT * FROM `Cases` WHERE `fk_caseTypeRef_id` = 53 and case_id not in
(SELECT fk_case_id FROM `MAIL_POLLER`);

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