Nsight Inc Interview Questions, Process, and Tips

WITH clause is used to define a temporary result set that can be used in a subsequent SQL statement.

• WITH clause is also known as Common Table Expression (CTE)

• It improves the readability and maintainability of complex SQL queries

• It can be used to simplify complex queries by breaking them down into smaller, more manageable parts

• It can be used to create recursive queries

• Example: WITH sales AS (SELECT * FROM sales_data) SE...read more

NTILE is a SQL function used to divide a result set into a specified number of groups.

• NTILE requires an integer argument that specifies the number of groups to divide the result set into.

• It assigns a group number to each row in the result set based on the specified number of groups.

• NTILE is often used in conjunction with the ORDER BY clause to divide the result set based on a specific column.

• NTILE can be used to calcul...read more

AS is used to assign an alias to a column or table in SQL, while IS is used to compare values or check for null values.

• AS is used in SELECT statements to assign a temporary name to a column or table

• AS can also be used in JOIN statements to assign aliases to tables

• IS is used in WHERE clauses to compare values or check for null values

• IS NULL is used to check if a value is null

• IS NOT NULL is used to check if a value is no

Case condition is used to perform conditional logic in SQL queries.

• It allows for conditional statements in SELECT, WHERE, and ORDER BY clauses.

• Syntax: CASE WHEN condition THEN result ELSE alternative END

• Can be nested for complex logic

• Useful for data transformation and reporting