mysql查询以选择一个特定行和另一个随机行

这对我很有用。第一个结果总是ID为5的记录,第二行是随机的。注意,如果不存在ID为5的记录,则这两行都是随机的。

SELECT * FROM users ORDER BY (user_id = 5) DESC, RAND() LIMIT 0,2 

试试这个

SELECT * FROM users WHERE user_id = 5 || user_id != 5 ORDER BY RAND() LIMIT 2

应该 玩把戏吧。你可能忘了 LIMIT .

(SELECT * FROM users WHERE user_id = 5 LIMIT 1)
UNION
(SELECT * FROM users WHERE user_id != 5 LIMIT 1)

SELECT * FROM users WHERE user_id=5
union all (
  SELECT * FROM  users WHERE user_id!=5
  ORDER BY RAND() LIMIT 0,1)