Question: How can I retrieve the Bottom N records from a query?
For example, what if I wanted to retrieve the last 3 records from my query results. How can I do this?
Answer: To retrieve the Bottom N records from a query, you can use the following syntax:
SELECT * FROM (your query ordered in reverse) alias_name WHERE rownum <= Rows_to_return ORDER BY rownum DESC;
If you want to retrieve the bottom records from a query, you need to order your results in reverse in the "your query ordered in reverse" section of the solution above.
For example, if you wanted to retrieve the last 3 records from the suppliers table, sorted by supplier_name in ascending order, you would run the following query:
SELECT * FROM (select * from suppliers ORDER BY supplier_name DESC) suppliers2 WHERE rownum <= 3 ORDER BY rownum DESC;
Notice that although you want the last 3 records sorted by supplier_name in ascending order, you actually sort the supplier_name in descending order in this solution.
If you wanted to retrieve the last 3 records from the suppliers table, sorted by supplier_name in descending order, you would run the following query:
SELECT * FROM (select * from suppliers ORDER BY supplier_name) suppliers2 WHERE rownum <= 3 ORDER BY rownum DESC;
If you wanted to retrieve the last 5 records from the suppliers table, sorted by supplier_id in ascending order, you would run the following query:
SELECT * FROM (select * from suppliers ORDER BY supplier_id DESC) suppliers2 WHERE rownum <= 5 ORDER BY rownum DESC;
If you wanted to retrieve the last 5 records from the suppliers table, sorted by supplier_id in descending order, you would run the following query:
SELECT * FROM (select * from suppliers ORDER BY supplier_id) suppliers2 WHERE rownum <= 5 ORDER BY rownum DESC;