How to display top 50 rows? code example

Example 1: rownum in sql

SELECT ROWNUM, a.*
FROM (SELECT customers.*
      FROM customers
      WHERE customer_id > 4500
      ORDER BY last_name) a;

Example 2: How to display top 50 rows?

In MySQL, top 50 rows are displayed by using this following query:
SELECT * FROM
LIMIT 0, 50;