1. ORACLE
SELECT * FROM TABLE1 WHERE ROWNUM<=N

2. INFORMIX
SELECT FIRST N * FROM TABLE1 where 1=1

3. DB2
SELECT * ROW_NUMBER() OVER(ORDER BY COL1 DESC) AS ROWNUM WHERE ROWNUM<=N
或者
SELECT COLUMN FROM TABLE where 1=1 FETCH FIRST N ROWS ONLY

4. SQL SERVER
SELECT TOP N * FROM TABLE1 where 1=1
or
SET ROWCOUNT N SELECT * FROM TABLE1 where 1=1 SET ROWCOUNT N1

5. SYBASE
SET ROWCOUNT N SELECT * FROM TABLE1 where 1=1 SET ROWCOUNT N1

6. MYSQL
SELECT * FROM TABLE1 where 1=1 LIMIT N

7. FOXPRO
SELECT * TOP N FROM TABLE ORDER BY COLUMN

8. ACCESS
SELECT TOP N * FROM TABLE1 where 1=1