Limit Function in Oracle

In Oracle, the LIMIT function is not a built-in function like in some other database systems such as MySQL. However, you can achieve similar functionality using the ROWNUM pseudo-column along with the ORDER BY clause. 

Here's an example of how you can use ROWNUM to limit the number of rows returned from a query:

Let's say you have a table called employees with columns employee_id, first_name, last_name, and you want to retrieve the first 5 employees ordered by employee_id:

SELECT *

FROM employees

WHERE ROWNUM <= 5

ORDER BY employee_id;

In this query:

- ROWNUM is a pseudo-column that returns a number indicating the order in which Oracle selects the row from a table or set of joined tables. 

- ROWNUM <= 5 restricts the result set to only include the first 5 rows.

- ORDER BY employee_id ensures that the results are sorted by the employee_id column before applying the row limiting condition.

This query will return the first 5 rows from the employees table, sorted by employee_id.

Keep in mind that ROWNUM is applied before ordering, so if you apply ROWNUM without sorting, the results might not be as expected. Therefore, it's essential to include an ORDER BY clause if you want the results to be ordered before applying the row limiting condition.