SQL Server: Common interview questions

1. What is the difference between Delete and Truncate in SQL Server?
2. What is trigger? Write syntax of trigger.
3. What is the difference between “char” and “varchar”?
4. What is function in Sql server? How many types of functions?
5. What is stored procedure? Write syntax of stored procedure?
6. How parameter is passed to sql function and how call a function?
7. What is input and output parameter in stored procedure? How it works?
8. Write syntax to create a table.
9. What is view? What is the difference between table and view?
10. What is constraint? Tell different type of constraint and its functionality.
11. Discuss different type of joining. How it works?
12. How left outer joining works?
13. How inner join works? Give an example.
14. How outer join works? Give an example.
15. How right outer join works? Give an example.
16. How full outer join works? Give an example?
17. How Cross Join works? Give an example?
18. Which one faster – Inner join or Cross Join?
19. How do you move all data to another table using query?
20. Find out the maximum salary from a salary table?
21. How do you find number of employee from employee table?
22. What is commit and rollback? How it works?
23. What do you know about transaction block? How it works?
24. How primary key constraints, foreign key constraints and default constraints works?
25. How not null constraints, check constraints, rules constraint and unique constraints works?
26. What are DDL and DML? Give example.
27. How distinct keyword works?
28. What do you know about sql wildcard? Give example.
29. How to select top 10 employees from employee table?
30. How “between” and “in” operator works?
31. Union / Union all, requirement and difference.
32. What is sub query? Give an example.
33. How “having” clause works?
34. How “group by” clause works?
35. Why “Where” clause is needed?