TransUnion Interview Questions, Process, and Tips

Regression is a software testing technique used to ensure that new code changes do not negatively impact existing functionality.

• Regression testing involves re-running previously executed test cases to verify that new code changes have not introduced any new bugs or issues.

• It helps ensure that the software continues to function correctly after modifications.

• Regression testing can be automated to save time and effort.

• Exa...read more

Use the DISTINCT keyword in a SELECT statement to remove duplicates in SQL.

• Use the DISTINCT keyword in a SELECT statement to retrieve unique rows

• Use GROUP BY clause with aggregate functions like COUNT() to remove duplicates based on specific columns

• Use ROW_NUMBER() function with PARTITION BY clause to remove duplicates and keep only one row

Different types of joins in SQL include inner join, outer join, left join, and right join.

• Inner join: Returns rows when there is a match in both tables

• Outer join: Returns all rows when there is a match in one of the tables

• Left join: Returns all rows from the left table and the matched rows from the right table

• Right join: Returns all rows from the right table and the matched rows from the left table