How to display last 7 record in single row in SQL

If you are using SQL Server then you can do something like following-

SELECT coulmn1,column2,...
FROM
(
    SELECT ROW_NUMBER() OVER (ORDER BY coulmn2 DESC) slno, * --where column2 is the column by which you can distinguish which are last records
    FROM MyTable
) as tbl
WHERE tbl.slno <= 7

Following query should also work but can be time consuming when you have large no of records. Good thing is it should work for all major DBMS.

SELECT TOP 7 *
FROM MyTable
ORDER BY Column2 DESC

Hope, it helps :)
Please let me know if you still have issue on this.