SELECT
(SELECT
MAX(`word_id`)
FROM
`tbl_user_words`
WHERE `member_id` = 1) AS max_id,
(SELECT
COUNT(`word_id`)
FROM
`tbl_user_words`
WHERE `right_count` < 5
AND `member_id` = 1) AS num ;
看起来怪怪的 ~
请将所有语句分开到代码中操作。。。。你看着不头痛么
这样的sql语句效率不高,建议拆分成多条,查询缓存的命中率会高一些。
试试这条语句, 帅气不?
SELECT MAX(`word_id`) AS max_id, SUM(`right_count` < 5) as num
FROM `tbl_user_words`
WHERE `member_id` = 1;
select max(t1.word_id) as max_id, count(t2.word_id) as num from tbl_user_words as t1, tbl_user_words as t2 where t1.member_id = 1 and t2.member_id = 1 and t2.right_count < 5
这样写可能清晰点。