Category: SQL

URL :https://dataford.io/sql/Population-Density-Analysis To get the maximum and minimum densities globally and sort cities by their density, you can use a subquery or a CTE as previously suggested. Here’s a step-by-step correction: approach two: explanation Population Density Calculation: The ROUND(population / Read more…

In the query provided for NTH_VALUE, don’t you need to include employee_name in a GROUP BY clause ?No, because you are using a window function and not performing aggregation that requires grouping. Window functions operate over a set of rows Read more…

Analytic Functions: a. LAG() b. LEAD() c. FIRST_VALUE() d. LAST_VALUE() E.NTH_VALUE() These examples use the sales and employee tables to show how window functions can be applied with multiple tables to provide context and derive meaningful insights

Let’s incorporate both tables (sales and employee) into the examples for window functions. We’ll use sales to show the data and apply window functions, and employee to provide additional context like employee names. Sample Data Table: sales Window Functions with Read more…

When learnig SQL at the beginig it may look like more complcated and confused , because when to use this window functions and whether do we need use GROUP BY satment for each of slected fileds .So here im going Read more…

source from ChatGBT Window functions in SQL provide a powerful and flexible way to perform calculations across sets of rows related to the current row without collapsing the result set like aggregation functions do. While alternatives (such as joins or Read more…