Location: Remote About the Internship: Kickstart your career with our Data Analytics Traineeship Program!Gain real-world experience through structured training, live projects, and professional reporting — ideal for students and fresh graduates. Responsibilities: Week 1 & 2: Complete assigned training modules. Week 3: Work on a live Data Analytics project. Week 4: Prepare and submit a … Read more
41. What is a Common Table Expression (CTE)? Answer: A temporary result set you can reference within a SELECT, INSERT, UPDATE, or DELETE. Example: WITH EmployeeCTE AS ( SELECT Name, DepartmentID FROM Employees WHERE Salary > 50000 ) SELECT * FROM EmployeeCTE; 42. What is Recursive CTE? Answer: A CTE that refers to itself to … Read more
31. What is Dynamic SQL? Answer: SQL commands constructed and executed at runtime. Example: DECLARE @sql NVARCHAR(MAX); SET @sql = ‘SELECT * FROM Employees WHERE DepartmentID = 2’; EXEC sp_executesql @sql; 32. How to prevent SQL Injection in Dynamic SQL? Answer: Always use parameterized queries instead of string concatenation. Example: DECLARE @DeptID INT = 2; … Read more
21. What is a Covering Index? Answer: An index that contains all the columns needed to satisfy a query without accessing the base table (reduces IO). Example: CREATE NONCLUSTERED INDEX idx_Covering ON Employees (Name, DepartmentID, Salary); 22. Explain Database Mirroring. Answer: A disaster recovery feature to keep two copies of a database synchronized (Principal and … Read more
11. What is CTE (Common Table Expression) and why use it? Answer: Temporary result set defined within the execution of a single SQL statement. Useful for improving readability and managing complex joins/queries. Example: WITH EmployeeCTE AS ( SELECT EmployeeID, Name, ManagerID FROM Employees ) SELECT * FROM EmployeeCTE; 12. What is a Recursive CTE? Answer: … Read more
1. What is a Partition By clause? Answer: It divides the result set into partitions and performs operations within each partition. Example: SELECT Name, Salary, RANK() OVER (PARTITION BY DepartmentID ORDER BY Salary DESC) AS DeptRank FROM Employees; 2. Explain PIVOT and UNPIVOT operations. Answer: PIVOT: Rotate rows into columns. UNPIVOT: Rotate columns into rows. … Read more
41. What is a self-join? Answer: A self-join is when a table joins to itself to compare rows within the same table. Example: SELECT A.Name AS Employee1, B.Name AS Employee2 FROM Employees A JOIN Employees B ON A.ManagerID = B.EmployeeID; 42. What is the difference between UNION and UNION ALL? Answer: UNION removes duplicate records. … Read more
31. What is a Common Table Expression (CTE)? Answer: A CTE is a temporary named result set that you can reference within a SELECT, INSERT, UPDATE, or DELETE. Example: WITH DepartmentCTE AS ( SELECT DepartmentID, COUNT(*) AS TotalEmployees FROM Employees GROUP BY DepartmentID ) SELECT * FROM DepartmentCTE; 32. What is a recursive CTE? Answer: … Read more
21. What is the difference between INNER JOIN and LEFT JOIN? Answer: INNER JOIN returns matching rows from both tables. LEFT JOIN returns all rows from the left table and matching rows from the right table. If no match, NULLs are returned. Example: — INNER JOIN SELECT E.Name, D.DepartmentName FROM Employees E INNER JOIN Departments … Read more
11. What are the types of user-defined functions in SQL? Answer: Scalar Functions — return a single value. Table-Valued Functions — return a table. 12. What is the difference between Scalar and Table-Valued Functions? Answer: Scalar Function returns one single value (like int, varchar). Table-Valued Function returns a full table. Example: — Scalar Function CREATE … Read more