SQL Server is a relational database management system developed by Microsoft. It is used to store and retrieve data as requested by other software applications.
2. What are the different editions of SQL Server?
The different editions of SQL Server include Enterprise, Standard, Express, and Developer editions.
3. What is a clustered index in SQL Server?
A clustered index in SQL Server determines the physical order of data in a table. It sorts and stores the rows in the table based on the key values.
4. What is a non-clustered index in SQL Server?
A non-clustered index in SQL Server does not affect the physical order of data in a table. It is stored separately from the table and contains pointers to the actual data.
5. What is a primary key in SQL Server?
A primary key in SQL Server is a unique identifier for each row in a table. It ensures that each row is uniquely identified and helps enforce data integrity.
6. What is a foreign key in SQL Server?
A foreign key in SQL Server is a field or a combination of fields that establishes a link between two tables. It enforces referential integrity between the two tables.
7. What is normalization in SQL Server?
Normalization is the process of organizing data in a database to reduce redundancy and improve data integrity. It involves breaking down tables into smaller, more manageable entities.
8. What is denormalization in SQL Server?
Denormalization is the process of adding redundant data to a database to improve query performance. It involves combining tables or adding duplicate data to eliminate the need for joins.
9. What is a stored procedure in SQL Server?
A stored procedure in SQL Server is a precompiled set of SQL statements that can be executed as a single unit. It is stored in the database and can be called by other applications.
10. What is a trigger in SQL Server?
A trigger in SQL Server is a special type of stored procedure that is automatically executed in response to certain events, such as insert, update, or delete operations on a table.
11. What is the difference between CHAR and VARCHAR data types in SQL Server?
CHAR is a fixed-length data type that stores a specific number of characters, while VARCHAR is a variable-length data type that stores up to a maximum number of characters.
12. What is the difference between UNION and UNION ALL in SQL Server?
UNION combines the results of two or more SELECT statements and removes duplicate rows, while UNION ALL combines the results of two or more SELECT statements without removing duplicate rows.
13. What is the difference between DELETE and TRUNCATE in SQL Server?
DELETE removes individual rows from a table based on a condition, while TRUNCATE removes all rows from a table without logging individual row deletions.
14. What is the difference between INNER JOIN and OUTER JOIN in SQL Server?
INNER JOIN returns rows when there is at least one match in both tables, while OUTER JOIN returns all rows from one table and only matching rows from the other table.
15. What is the difference between a clustered and non-clustered index in SQL Server?
A clustered index determines the physical order of data in a table, while a non-clustered index does not affect the physical order of data and is stored separately from the table.
16. What is the difference between a primary key and a unique key in SQL Server?
A primary key is a unique identifier for each row in a table and cannot contain NULL values, while a unique key enforces uniqueness but allows NULL values.
17. What is the difference between a view and a table in SQL Server?
A view is a virtual table that is based on the result set of a SELECT statement, while a table is a physical storage structure that contains data.
18. What is the difference between a function and a stored procedure in SQL Server?
A function returns a value and can be used in SELECT statements, while a stored procedure does not return a value and can perform multiple operations.
19. What is the difference between a subquery and a join in SQL Server?
A subquery is a query nested within another query, while a join is used to combine rows from two or more tables based on a related column between them.
20. What is the difference between a scalar function and a table-valued function in SQL Server?
A scalar function returns a single value, while a table-valued function returns a table as a result set.
21. What is the difference between a clustered and non-clustered index in SQL Server?
A clustered index determines the physical order of data in a table, while a non-clustered index does not affect the physical order of data and is stored separately from the table.
22. What is the difference between a primary key and a unique key in SQL Server?
A primary key is a unique identifier for each row in a table and cannot contain NULL values, while a unique key enforces uniqueness but allows NULL values.
23. What is the difference between a view and a table in SQL Server?
A view is a virtual table that is based on the result set of a SELECT statement, while a table is a physical storage structure that contains data.
24. What is the difference between a function and a stored procedure in SQL Server?
A function returns a value and can be used in SELECT statements, while a stored procedure does not return a value and can perform multiple operations.
25. What is the difference between a subquery and a join in SQL Server?
A subquery is a query nested within another query, while a join is used to combine rows from two or more tables based on a related column between them.
26. What is the difference between a scalar function and a table-valued function in SQL Server?
A scalar function returns a single value, while a table-valued function returns a table as a result set.
27. What is the difference between a clustered and non-clustered index in SQL Server?
A clustered index determines the physical order of data in a table, while a non-clustered index does not affect the physical order of data and is stored separately from the table.
28. What is the difference between a primary key and a unique key in SQL Server?
A primary key is a unique identifier for each row in a table and cannot contain NULL values, while a unique key enforces uniqueness but allows NULL values.
29. What is the difference between a view and a table in SQL Server?
A view is a virtual table that is based on the result set of a SELECT statement, while a table is a physical storage structure that contains data.
30. What is the difference between a function and a stored procedure in SQL Server?
A function returns a value and can be used in SELECT statements, while a stored procedure does not return a value and can perform multiple operations.
31. What is the difference between a subquery and a join in SQL Server?
A subquery is a query nested within another query, while a join is used to combine rows from two or more tables based on a related column between them.
32. What is the difference between a scalar function and a table-valued function in SQL Server?
A scalar function returns a single value, while a table-valued function returns a table as a result set.
33. What is the difference between a clustered and non-clustered index in SQL Server?
A clustered index determines the physical order of data in a table, while a non-clustered index does not affect the physical order of data and is stored separately from the table.
34. What is the difference between a primary key and a unique key in SQL Server?
A primary key is a unique identifier for each row in a table and cannot contain NULL values, while a unique key enforces uniqueness but allows NULL values.
35. What is the difference between a view and a table in SQL Server?
A view is a virtual table that is based on the result set of a SELECT statement, while a table is a physical storage structure that contains data.
36. What is the difference between a function and a stored procedure in SQL Server?
A function returns a value and can be used in SELECT statements, while a stored procedure does not return a value and can perform multiple operations.
37. What is the difference between a subquery and a join in SQL Server?
A subquery is a query nested within another query, while a join is used to combine rows from two or more tables based on a related column between them.
38. What is the difference between a scalar function and a table-valued function in SQL Server?
A scalar function returns a single value, while a table-valued function returns a table as a result set.
39. What is the difference between a clustered and non-clustered index in SQL Server?
A clustered index determines the physical order of data in a table, while a non-clustered index does not affect the physical order of data and is stored separately from the table.
40. What is the difference between a primary key and a unique key in SQL Server?
A primary key is a unique identifier for each row in a table and cannot contain NULL values, while a unique key enforces uniqueness but allows NULL values.
41. What is the difference between a view and a table in SQL Server?
A view is a virtual table that is based on the result set of a SELECT statement, while a table is a physical storage structure that contains data.
42. What is the difference between a function and a stored procedure in SQL Server?
A function returns a value and can be used in SELECT statements, while a stored procedure does not return a value and can perform multiple operations.
43. What is the difference between a subquery and a join in SQL Server?
A subquery is a query nested within another query, while a join is used to combine rows from two or more tables based on a related column between them.
44. What is the difference between a scalar function and a table-valued function in SQL Server?
A scalar function returns a single value, while a table-valued function returns a table as a result set.
45. What is the difference between a clustered and non-clustered index in SQL Server?
A clustered index determines the physical order of data in a table, while a non-clustered index does not affect the physical order of data and is stored separately from the table.
46. What is the difference between a primary key and a unique key in SQL Server?
A primary key is a unique identifier for each row in a table and cannot contain NULL values, while a unique key enforces uniqueness but allows NULL values.
47. What is the difference between a view and a table in SQL Server?
A view is a virtual table that is based on the result set of a SELECT statement, while a table is a physical storage structure that contains data.
48. What is the difference between a function and a stored procedure in SQL Server?
A function returns a value and can be used in SELECT statements, while a stored procedure does not return a value and can perform multiple operations.
49. What is the difference between a subquery and a join in SQL Server?
A subquery is a query nested within another query, while a join is used to combine rows from two or more tables based on a related column between them.
50. What is the difference between a scalar function and a table-valued function in SQL Server?
A scalar function returns a single value, while a table-valued function returns a table as a result set.
51. What is the difference between a clustered and non-clustered index in SQL Server?
A clustered index determines the physical order of data in a table, while a non-clustered index does not affect the physical order of data and is stored separately from the table.
52. What is the difference between a primary key and a unique key in SQL Server?
A primary key is a unique identifier for each row in a table and cannot contain NULL values, while a unique key enforces uniqueness but allows NULL values.
53. What is the difference between a view and a table in SQL Server?
A view is a virtual table that is based on the result set of a SELECT statement, while a table is a physical storage structure that contains data.
54. What is the difference between a function and a stored procedure in SQL Server?
A function returns a value and can be used in SELECT statements, while a stored procedure does not return a value and can perform multiple operations.
55. What is the difference between a subquery and a join in SQL Server?
A subquery is a query nested within another query, while a join is used to combine rows from two or more tables based on a related column between them.
56. What is the difference between a scalar function and a table-valued function in SQL Server?
A scalar function returns a single value, while a table-valued function returns a table as a result set.
57. What is the difference between a clustered and non-clustered index in SQL Server?
A clustered index determines the physical order of data in a table, while a non-clustered index does not affect the physical order of data and is stored separately from the table.
58. What is the difference between a primary key and a unique key in SQL Server?
A primary key is a unique identifier for each row in a table and cannot contain NULL values, while a unique key enforces uniqueness but allows NULL values.
59. What is the difference between a view and a table in SQL Server?
A view is a virtual table that is based on the result set of a SELECT statement, while a table is a physical storage structure that contains data.
60. What is the difference between a function and a stored procedure in SQL Server?
A function returns a value and can be used in SELECT statements, while a stored procedure does not return a value and can perform multiple operations.
61. What is the difference between a subquery and a join in SQL Server?
A subquery is a query nested within another query, while a join is used to combine rows from two or more tables based on a related column between them.
62. What is the difference between a scalar function and a table-valued function in SQL Server?
A scalar function returns a single value, while a table-valued function returns a table as a result set.
63. What is the difference between a clustered and non-clustered index in SQL Server?
A clustered index determines the physical order of data in a table, while a non-clustered index does not affect the physical order of data and is stored separately from the table.
64. What is the difference between a primary key and a unique key in SQL Server?
A primary key is a unique identifier for each row in a table and cannot contain NULL values, while a unique key enforces uniqueness but allows NULL values.
65. What is the difference between a view and a table in SQL Server?
A view is a virtual table that is based on the result set of a SELECT statement, while a table is a physical storage structure that contains data.
66. What is the difference between a function and a stored procedure in SQL Server?
A function returns a value and can be used in SELECT statements, while a stored procedure does not return a value and can perform multiple operations.
67. What is the difference between a subquery and a join in SQL Server?
A subquery is a query nested within another query, while a join is used to combine rows from two or more tables based on a related column between them.
68. What is the difference between a scalar function and a table-valued function in SQL Server?
A scalar function returns a single value, while a table-valued function returns a table as a result set.
69. What is the difference between a clustered and non-clustered index in SQL Server?
A clustered index determines the physical order of data in a table, while a non-clustered index does not affect the physical order of data and is stored separately from the table.
70. What is the difference between a primary key and a unique key in SQL Server?
A primary key is a unique identifier for each row in a table and cannot contain NULL values, while a unique key enforces uniqueness but allows NULL values.
71. What is the difference between a view and a table in SQL Server?
A view is a virtual table that is based on the result set of a SELECT statement, while a table is a physical storage structure that contains data.
72. What is the difference between a function and a stored procedure in SQL Server?
A function returns a value and can be used in SELECT statements, while a stored procedure does not return a value and can perform multiple operations.
73. What is the difference between a subquery and a join in SQL Server?
A subquery is a query nested within another query, while a join is used to combine rows from two or more tables based on a related column between them.
74. What is the difference between a scalar function and a table-valued function in SQL Server?
A scalar function returns a single value, while a table-valued function returns a table as a result set.
75. What is the difference between a clustered and non-clustered index in SQL Server?
A clustered index determines the physical order of data in a table, while a non-clustered index does not affect the physical order of data and is stored separately from the table.
76. What is the difference between a primary key and a unique key in SQL Server?
A primary key is a unique identifier for each row in a table and cannot contain NULL values, while a unique key enforces uniqueness but allows NULL values.
77. What is the difference between a view and a table in SQL Server?
A view is a virtual table that is based on the result set of a SELECT statement, while a table is a physical storage structure that contains data.
78. What is the difference between a function and a stored procedure in SQL Server?
A function returns a value and can be used in SELECT statements, while a stored procedure does not return a value and can perform multiple operations.
79. What is the difference between a subquery and a join in SQL Server?
A subquery is a query nested within another query, while a join is used to combine rows from two or more tables based on a related column between them.
80. What is the difference between a scalar function and a table-valued function in SQL Server?
A scalar function returns a single value, while a table-valued function returns a table as a result set.
81. What is the difference between a clustered and non-clustered index in SQL Server?
A clustered index determines the physical order of data in a table, while a non-clustered index does not affect the physical order of data and is stored separately from the table.
82. What is the difference between a primary key and a unique key in SQL Server?
A primary key is a unique identifier for each row in a table and cannot contain NULL values, while a unique key enforces uniqueness but allows NULL values.
83. What is the difference between a view and a table in SQL Server?
A view is a virtual table that is based on the result set of a SELECT statement, while a table is a physical storage structure that contains data.
84. What is the difference between a function and a stored procedure in SQL Server?
A function returns a value and can be used in SELECT statements, while a stored procedure does not return a value and can perform multiple operations.
85. What is the difference between a subquery and a join in SQL Server?
A subquery is a query nested within another query, while a join is used to combine rows from two or more tables based on a related column between them.
86. What is the difference between a scalar function and a table-valued function in SQL Server?
A scalar function returns a single value, while a table-valued function returns a table as a result set.
87. What is the difference between a clustered and non-clustered index in SQL Server?
A clustered index determines the physical order of data in a table, while a non-clustered index does not affect the physical order of data and is stored separately f