查询前几条记录在不同数据库中的用法

1. ORACLE

SELECT * FROM TABLE1 WHERE ROWNUM<=N

2. DB2

SELECT * ROW_NUMBER() OVER(ORDER BY COL1 DESC) AS ROWNUM WHERE ROWNUM<=N

或者

SELECT COLUMN FROM TABLE FETCH FIRST N ROWS ONLY

3. SQL SERVER

SELECT TOP N * FROM TABLE1

4. SYBASE

SET ROWCOUNT N

GO

SELECT * FROM TABLE1

5. MYSQL

SELECT * FROM TABLE1 LIMIT N

要实现先排序,再取前几名用下面这条语句

select * from (select * from table order by 字段名 desc) where rownum<n