Select Top在不同數據庫中的使用用法：
1. Oracle數據庫
SELECT * FROM TABLE1 WHERE ROWNUM<=N
2. Infomix數據庫
SELECT FIRST N * FROM TABLE1
3. DB2數據庫
SELECT * ROW_NUMBER() OVER(ORDER BY COL1 DESC) AS ROWNUM WHERE ROWNUM<=N
或者
SELECT COLUMN FROM TABLE FETCH FIRST N ROWS ONLY
4. SQL Server數據庫
SELECT TOP N * FROM TABLE1
5. Sybase數據庫
SET ROWCOUNT N
GO
SELECT * FROM TABLE1
6. MySQL數據庫
SELECT * FROM TABLE1 LIMIT N
7. FoxPro數據庫
SELECT * TOP N FROM TABLE ORDER BY COLUMN
