SQL RDBMS - Beginner & Intermediate - Top 80 Interview Questions

1. What is SQL?
2. What is the difference between SQL and NoSQL?
3. What are the different types of SQL commands?
4. What is a primary key?
5. What is a foreign key?
6. What is normalization in SQL?
7. What is denormalization in SQL?
8. What is an index in SQL?
9. What is a clustered index?
10. What is a non-clustered index?
11. What is a join in SQL?
12. What are the different types of joins in SQL?
13. What is a subquery in SQL?
14. What is a correlated subquery?
15. What is a self-join?
16. What is a union in SQL?
17. What is a view in SQL?
18. What is a stored procedure in SQL?
19. What is a trigger in SQL?
20. What is a cursor in SQL?
21. What is a transaction in SQL?
22. What is ACID in SQL?
23. What is a deadlock in SQL?
24. What is a constraint in SQL?
25. What is a check constraint in SQL?
26. What is a unique constraint in SQL?
27. What is a default constraint in SQL?
28. What is a foreign key constraint in SQL?
29. What is a primary key constraint in SQL?
30. What is a composite key?
31. What is a computed column in SQL?
32. What is a scalar function in SQL?
33. What is a table-valued function in SQL?
34. What is a temporary table in SQL?
35. What is a transaction log in SQL?
36. What is a backup in SQL?
37. What is a restore in SQL?
38. What is a database schema in SQL?
39. What is a database trigger in SQL?
40. What is the difference between truncate and delete?
41. What is the difference between clustered and non-clustered indexes?
42. What is the difference between inner and outer joins?
43. What is the difference between a stored procedure and a function?
44. What is the difference between a view and a table?
45. What is the difference between a trigger and a procedure?
46. How do you handle errors in SQL?
47. How do you optimize SQL queries?
48. How do you debug SQL queries?
49. How do you optimize database performance in SQL?
50. How do you improve database security in SQL?
51. What is the difference between a primary key and a unique key?
52. What is the difference between a left join and a right join?
53. What is the difference between a transaction and a batch?
54. What is a collation in SQL?
55. What is a scalar subquery in SQL?
56. What is a self-contained subquery in SQL?
57. What is the difference between an aggregate function and a scalar function?
58. What is a recursive query in SQL?
59. What is the difference between a view and a materialized view?
60. What is a full-text search in SQL?
61. What is the difference between a char and a varchar data type?
62. What is the difference between a float and a decimal data type?
63. What is the difference between a date and a datetime data type?
64. What is the difference between a stored procedure and a trigger?
65. What is a temporary table and why would you use one?
66. What is the difference between a transaction and a savepoint?
67. What is the difference between a left join and a full join?
68. What is the difference between a clustered and a non-clustered index?
69. What is a correlated subquery and when would you use one?
70. What is the difference between a subquery and a join?
71. What is the difference between a grant and a revoke statement in SQL?
72. What is a database index and how does it work?
73. What is a deadlock in SQL and how can it be avoided?
74. What is the difference between a database and a tablespace?
75. What is a data dictionary in SQL?
76. What is the difference between a DDL and a DML statement in SQL?
77. What is a schema in SQL?
78. What is the difference between an inner join and a cross join?
79. What is the difference between an identity column and a sequence in SQL Server?
80. What is a correlated subquery and when would you use one?