Un NOT IN() la sottoquery può essere utilizzata qui, poiché MySQL non supporta MINUS .
SELECT
cand_email
FROM tbl_cand_data
WHERE can_email NOT IN (SELECT un_email FROM tbl_unsubscribe)
Può anche essere fatto con un LEFT JOIN , cercando NULL in un_email colonna:
SELECT cand_email
FROM
tbl_cand_data
LEFT JOIN tbl_unsubscribe ON tbl_cand_data.can_email = tbl_unsubscribe.un_email
WHERE tbl_unsubscribe.un_email IS NULL
Per escluderli da un mucchio di UNION operazioni, avvolgere il UNION gruppo in () come sottoquery:
SELECT email FROM (
SELECT cand_email AS email FROM tbl_cand_data
UNION
SELECT emp_email AS email FROM tbl_emp_data
UNION
SELECT email FROM AS email tbl_uptade_list
UNION
SELECT feed_email AS email FROM tbl_feedback
UNION
SELECT admin_email AS email FROM tbl_admin_emails
) email_list
WHERE email NOT IN (SELECT un_email FROM tbl_unsubscribe)
