DataMetica fresher Engineer Interview Questions and Answers

Use SQL query with GROUP BY and HAVING clause to find duplicate entries in a table.

• Use GROUP BY clause to group the rows based on the columns that you suspect may have duplicates.

• Use COUNT() function to count the number of occurrences of each group.

• Use HAVING clause to filter out groups that have more than one occurrence, indicating duplicates.

• Example: SELECT column1, column2, COUNT(*) FROM table_name GROUP BY column1,

Use subquery to find 3 highest salaries in Employee table without using limit or offset function

• Use subquery to select distinct salaries from Employee table

• Order the distinct salaries in descending order

• Select top 3 salaries from the ordered list