mysql隨機(jī)查詢(xún)?nèi)舾蓷l數(shù)據(jù)的方法？1.隨機(jī)讀取連續(xù)多條記錄。經(jīng)過(guò)實(shí)踐，可以隨機(jī)讀取多條連續(xù)的數(shù)據(jù)記錄，里頭取值的一般都是主鍵ID來(lái)進(jìn)行最大值、最小值的讀?。篠ELECT * FROM example

mysql隨機(jī)查詢(xún)?nèi)舾蓷l數(shù)據(jù)的方法？

1.隨機(jī)讀取連續(xù)多條記錄。經(jīng)過(guò)實(shí)踐，可以隨機(jī)讀取多條連續(xù)的數(shù)據(jù)記錄，里頭取值的一般都是主鍵ID來(lái)進(jìn)行最大值、最小值的讀?。?/p>

SELECT * FROM example_table AS t1 JOIN (SELECT ROUND(RAND() * ((SELECT MAX(id) FROM example_table)-(SELECT MIN(id) FROM example_table)) (SELECT MIN(id) FROM example_table)) AS id) AS t2 WHERE t1.id >= t2.id ORDER BY t1.id LIMIT 5

2.隨機(jī)多條數(shù)據(jù)。以下兩種都是隨機(jī)讀取數(shù)據(jù)，查詢(xún)數(shù)據(jù)速度、隨機(jī)范圍都基本相差不大

SELECT * FROM example_table WHERE id >= ((SELECT MAX(id) FROM example_table)-(SELECT MIN(id) FROM example_table)) * RAND() (SELECT MIN(id) FROM example_table) LIMIT 5

SELECT * FROM example_table WHERE id>=(SELECT floor(RAND() * ((SELECT MAX(id) FROM example_table)-(SELECT MIN(id) FROM example_table)) (SELECT MIN(id) FROM example_table))) ORDER BY id LIMIT 5

MYSQL隨機(jī)調(diào)取多個(gè)數(shù)值？

從1到1000范圍內(nèi)隨機(jī)一個(gè)數(shù)字mt_rand(1，1000)

查詢(xún)下這個(gè)數(shù)字 在這個(gè)表中的aid存不存在

用while去判斷下

$aidarr = array()

while (count($aidarr )

{

$randnum = mt_rand(1，1000)

$sql = "select count(aid) from dede_addonproducts where aid=$randnum"

$aid = $db->query($sql)

if ($aid == 1)

{

$aidarr[] = $randnum

}

}

這時(shí)候$aidarr還是數(shù)組不是字符串

然后用for 導(dǎo)入一下

for ($i=0$i

MySQL產(chǎn)生隨機(jī)數(shù)？

select round(round(rand()，4)*10000)不用函數(shù)直接這樣就好了。非得寫(xiě)函數(shù)的話(huà)，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