What is Unique key and Primary key in SQL?

What is Unique key and Primary key in SQL? This is one of the most frequently asked interview question. Before we discuss difference between these two let us see what is primary key and unique key. What is Primary key? Primary key is the key which uniquely identify each and every record in the table. … Read more What is Unique key and Primary key in SQL?

What is the difference between Union and Union ALL? | SQL Queries

Here we will see the practical examples after reading this article you will be able to understand the major difference between union and union all. This is one of the commonly asked interview question. One should answer this question because it is a very basic question in SQL People often confuse when an interviewer ask … Read more What is the difference between Union and Union ALL? | SQL Queries