问题:

I have a table A which consists more than 7k records,Now i am creating a new table B .In my new table B I need to copy only 1000 records from table A which has more than 7000 records.

No condition applies, it may be any thousand records from 7000 .

回答1:

In SQL Server

SELECT top 1000 *
INTO newTableName
FROM oldTableName;

In MySQL

SELECT *
INTO newTableName
FROM oldTableName Limit 1000;

回答2:

INSERT INTO TABLEB(Col1, Col2, .... colN)
    SELECT TOP 1000 Col1, Col2, .... colN FROM TABLEA

回答3:

You can use ROW_NUMBER in a common table expression.

WITH CTE AS(
   SELECT Col1, Col2, Col3, RN = ROW_NUMBER() OVER (ORDER BY Col1)
   FROM dbo.TableA
)
INSERT INTO dbo.TableB(Col1, Col2, Col3)
    SELECT Col1, Col2, Col3
    FROM CTE
    WHERE RN <= 1000

Then it's easy to change the logic what should be exported. You could change the ORDER BY, apply a PARTITION BY(f.e. to copy duplicates), use multiple ORDER BY comma separated or change the number you want to export.