为什么此查询不起作用？ (我试图替换嵌套的IF语句“… SET lkey = IF(lkey> = 11，lkey-5，IF(lkey> 5，lkey 2，lkey)
@H_502_4@UPDATE pages
SET lkey = CASE lkey WHEN lkey >= 11 THEN
lkey - 5
ELSE
CASE lkey WHEN lkey > 5 THEN
lkey + 2
ELSE
lkey
END
END,rkey = CASE lkey WHEN lkey >= 11 THEN
rkey - 5
ELSE
CASE rkey WHEN rkey < 11 THEN
rkey + 2
ELSE
rkey
END
END
WHERE rkey > 5 AND
lkey < 12;
