SQL Server

Question 1

What are the two authentication modes in SQL Server?

Answer 1

Windows Mode and Mixed Mode

Question 2

What Is SQL Profiler?

Answer 2

Microsoft SQL Server Profiler is a graphical user interface to SQL Trace for monitoring an instance of the Database Engine or Analysis Services.

Microsoft SQL Server Profiler is now depricated.

Question 3

What are the differences between local and global temporary tables?

Answer 3

Local temporary tables are visible when there is a connection, and are deleted when the connection is closed.

Question 4

What is COALESCE in SQL Server?

Answer 4

COALESCE is used to return the first non-null expression within the arguments. This function is used to return a non-null from more than one column in the arguments.

Question 5

What does UNION do?

Answer 5

UNION merges the contents of two structurally-compatible tables into a single combined table.

Question 6

What is the difference between UNION and UNION ALL?

Answer 6

UNION will omit duplicate records whereas UNION ALL will include duplicate records.

Question 7

What are the 3 types of SQL statements?

Answer 7

1. DDL (Data Definition Language): It is used to define the database structure such as tables. It includes three statements such as Create, Alter, and Drop.
2. DML (Data Manipulation Language): These statements are used to manipulate the data in records. Commonly used DML statements are Insert, Update, and Delete.
3. DCL (Data Control Language): These statements are used to set privileges such as Grant and Revoke database access permission to the specific user.

Question 8

What is Referential Integrity?

Answer 8

Set of rules that restrict the values of one or more columns of the tables based on the values of the primary key or unique key of the referenced table.

Question 9

What is Collation?

Answer 9

Set of rules that define how data is stored, how case sensitivity and Kana character can be treated etc.