1,系統時間
Oracle:SYSDATE
SQLSever:getdate()
Access:date() 或者 now()
2,查詢前n條記錄
Oracel: Select * From (Select……) where rownum<=10 ((Select……)是要真正查詢的語句)
SQLServer:Select * From…………Top 10
MySql:Select * From tablename Limit 10
3, 隨即抽取
MySql: FROM `table` AS t1 JOIN (SELECT ROUND(RAND() * ((SELECT MAX(id) FROM `table`)-(SELECT MIN(id) FROM `table`))+(SELECT MIN(id) FROM `table`)) AS id) AS t2 WHERE t1.id >= t2.id ORDER BY t1.id LIMIT 1;