sql隨機函數(shù)rand怎么用 MySQL產(chǎn)生隨機數(shù)?
MySQL產(chǎn)生隨機數(shù)?select round(round(rand(),4)*10000)不用函數(shù)直接這樣就好了。非得寫函數(shù)的話,就DELIMITER $$CREATE FUNCTION ge
MySQL產(chǎn)生隨機數(shù)?
select round(round(rand(),4)*10000)不用函數(shù)直接這樣就好了。非得寫函數(shù)的話,就DELIMITER $$CREATE FUNCTION get_rand() RETURNS INT DETERMINISTIC BEGIN DECLARE return_no INT SELECT ROUND(ROUND(RAND(),4)*10000) INTO return_no RETURN return_no END$$DELIMITER
mysql如何生成不重復的隨機數(shù)?
mysql的rand函數(shù)可以生成一個0到1之間的隨機數(shù),進行一定的放大即可得到一個隨機數(shù)。再通過條件查詢來限制新隨機數(shù)沒有在表中出現(xiàn)過。如下所示:
SELECT FLOOR(RAND() * 99999) AS random_numFROM numbers
WHERE "random_num" NOT IN (SELECT my_number FROM numbers)
LIMIT 1