One of the most common SQL interview questions is to find the Nth highest salary of employees, where N could be 2, 3, 4 or anything e.g. find the second highest salary in SQL. Sometimes this question is also twisted as to find the nth minimum salary in SQL. Since many Programmers only know the easy way to solve this problem e.g. by using SQL IN clause, which doesn't scale well, they struggle to write the SQL query when the Interviewer keeps asking about the 4th highest, 5th highest and so on. In order to solve this problem effectively, you need to know about some key concepts like a correlated subquery, window functions like ROW_NUMER(), RANK(), and DENSE_RANK(), etc. Once you know the generic logic to solve this problem, you can tackle all those variations by yourself.
Difference between application/x-www-form-urlencoded and multipart/form-data in HTTP/HTML?
Recently in one of the Java web developer interview, one of my readers asked about the difference between x-www-form-url-encoded and multipart/form-data MIME types. In HTTP, there are two ways to send the HTML form data to the server either by using ContentType application/x-www-form-urlencoded or by using multipart/form-data. Even though both can be used to send both text and binary data to the server there is a subtle difference between them. In the case of x-www-form-urlencoded, the whole form data is sent as a long query string.
Subscribe to:
Posts
(
Atom
)