隨機取得資料:各種資料庫語法

之前發現的一篇文章,以後隨時可參考
出處忘了保留,Sorry...

There are lots of ways to select a random record or row from a database table. Here are some example SQL statements that don't require additional application logic, but each database server requires different SQL syntax.


Select a random row with MySQL:

SELECT column FROM table
ORDER BY RAND()
LIMIT 1
--------------------------------------
Select a random row with PostgreSQL:

SELECT column FROM table
ORDER BY RANDOM()
LIMIT 1
--------------------------------------
Select a random row with Microsoft SQL Server:

SELECT TOP 1 column FROM table
ORDER BY NEWID()
--------------------------------------
Select a random row with IBM DB2

SELECT column, RAND() as IDX
FROM table
ORDER BY IDX FETCH FIRST 1 ROWS ONLY
--------------------------------------
Select a random record with Oracle:

SELECT column FROM
( SELECT column FROM table
ORDER BY dbms_random.value )
WHERE rownum = 1