就像是:
SELECT id, email, IF(active = 1, 'enabled', 'disabled') AS account_status FROM users
这使您可以进行操作并将其显示为列。
编辑:
您还可以使用联接并将操作显示为列:
SELECT u.id, e.email, IF(c.id IS NULL, 'no selected', c.name) AS country
FROM users u LEFT JOIN countries c ON u.country_id = c.id