Cognizant SQL Questions

SQL is the one skill both Cognizant clusters share — whether you chose Java/Web UI or Python/Cloud, the technical assessment sets ANSI SQL tasks, and interviewers routinely ask you to write queries live. The classics below appear in memory-based Cognizant papers again and again.

The Cognizant SQL hit-list

• Second highest salary (subquery with MAX)
• Nth highest salary (DENSE_RANK window function)
• Employees earning more than their managers (self-join)
• Duplicate emails (GROUP BY … HAVING)
• Customers who never order (LEFT JOIN … IS NULL / NOT IN)
• Deleting duplicates while keeping the smallest id

Practice Cognizant SQL questions

Each question below is one of those classics in MCQ form — pick the query you would actually run.

Q1SQL Subqueries

Which SQL query reports the second highest salary from the Employee table (returning NULL if it does not exist)?

ASELECT MAX(salary) FROM Employee WHERE salary < (SELECT MAX(salary) FROM Employee);BSELECT MAX(salary) FROM Employee ORDER BY salary DESC LIMIT 2;CSELECT salary FROM Employee WHERE salary = MAX(salary) - 1;DSELECT MIN(salary) FROM Employee;

Q2SQL Joins

Which SQL query finds all employees earning more than their managers?

ASELECT e.name FROM Employee e JOIN Employee m ON e.managerId = m.id WHERE e.salary > m.salary;BSELECT name FROM Employee WHERE salary > managerId;CSELECT name FROM Employee GROUP BY managerId HAVING salary > MAX(salary);DSELECT e.name FROM Employee e WHERE e.salary > (SELECT MAX(salary) FROM Employee);

Q3SQL Grouping

Which SQL query finds all duplicate emails in a Person table?

ASELECT email FROM Person WHERE COUNT(email) > 1;BSELECT email FROM Person GROUP BY email HAVING COUNT(email) > 1;CSELECT DISTINCT email FROM Person;DSELECT email FROM Person ORDER BY COUNT(email);

Do not just recognize the right query — practice typing each one from a blank editor. The interview version of this section is “share your screen and write it”, and hesitation is what costs offers.

Pair SQL with your cluster's coding practice on the coding questions page, and revisit joins/grouping theory before the technical interview.