How to use ROW_NUMBER() Function in SQL with nondeterministic order? Example Tutorial

The ROW NUMBER window function has a wide range of uses, much beyond the apparent ordering requirements. Most of the time, while computing row numbers, you need to do it in a specified order, which you provide in the function's window order clause. 

How to Remove duplicate rows from table in SQL Server using temp table? Example

One of the easiest way to remove duplicate rows from a table in SQL is copy unique data into temp table, delete the original table and create a new table from the temp table without any duplicates. Sometime when you don't have a unique key or primary key in table, you end up with duplicate rows i.e. more than one rows where all columns are identical. You can easily find those duplicate rows by using GRPUP BY, as seen in our previous SQL interview questions. You can also print just unique rows by using distinct clause, but how do you go about removing duplicate rows from table altogether? That's what you will learn in this article. Actually there are multiple ways to remove duplicates and you will learn couple of them in this article. 

How to calculate Running Total and Running Average in SQL (with PARTITION BY Example)

Hello guys, calculating running totals and running averages is a common requirement in data analysis and reporting but I have interviewed many people who have no clue on how to do this. If you have also seen this question on interview and struggle to answer then you have come to the right place. SQL provides powerful features like window functions,which can be used to compute these running aggregates or running totals. In this article, we'll explore the concepts of running total and running average in SQL and see the real world examples and explanations to help you master these calculations but before that let's find out what is running total actually means?