ORACLE:
SELECT * FROM (SELECT * FROM T_USER ORDER BY DBMS_RANDOM.RANDOM()) WHERE RONUM <= 10
MySQL:
SELECT * FROM T_USER ORDER BY RAND() LIMIT 10
SQL Server:
SELECT TOP 10 * FROM T_USER ORDER BY NEWID()
Access:
SELECT TOP 10 * FROM T_USER ORDER BY rnd([一个自动编号字段])
