Here are top Microsoft SQL Server interview questions,
1. What is Microsoft SQL Server?
Microsoft
SQL Server is a relational database management system (RDBMS) developed by
Microsoft. It is used to store and manage data in a structured format.
2. How do you create a new database
in SQL Server?
To create a
new database in SQL Server, you can use the following SQL query:
```sql
CREATE DATABASE database_name;
```
3. How do you connect to a SQL
Server database using SQL Server Management Studio (SSMS)?
Open SSMS,
click "Connect" in the "Connect to Server" window, then
select the appropriate server name and authentication method (e.g., Windows
Authentication or SQL Server Authentication).
4. What is the command to create a
new table in SQL Server?
To create a
new table in SQL Server, use the following SQL query:
```sql
CREATE TABLE table_name (
column1 datatype constraints,
column2 datatype constraints,
...
);
```
5. How do you insert data into a SQL
Server table?
To insert
data into a table, use the `INSERT INTO` statement as follows:
```sql
INSERT INTO table_name (column1, column2,
...)
VALUES (value1, value2, ...);
```
6. What is the difference between
`CHAR` and `VARCHAR` data types in SQL Server?
`CHAR` is a
fixed-length string type, while `VARCHAR` is a variable-length string type in
SQL Server. `VARCHAR` will use only as much storage as needed, whereas `CHAR`
will always use the specified length.
7. How can you retrieve all records
from a table in SQL Server?
You can use
the `SELECT` statement without specifying any conditions to retrieve all
records:
```sql
SELECT * FROM table_name;
```
8. What is the purpose of the
`WHERE` clause in SQL Server?
The `WHERE`
clause is used to filter records in a `SELECT`, `UPDATE`, or `DELETE` statement
based on specified conditions.
9. How do you update data in a SQL
Server table?
To update
data in a table, use the `UPDATE` statement as follows:
```sql
UPDATE table_name
SET column1 = value1, column2 = value2,
...
WHERE condition;
```
10. How can you delete records from
a SQL Server table?
To delete
records from a table, use the `DELETE FROM` statement along with the `WHERE`
clause to specify the condition for deletion:
```sql
DELETE FROM table_name
WHERE condition;
```
11. What is the use of the `TOP`
clause in SQL Server?
The `TOP`
clause is used to restrict the number of rows returned by a `SELECT` query. It
helps in pagination or when you want to retrieve a specific number of rows.
12. How do you add a new column to
an existing SQL Server table?
To add a
new column to an existing table, use the `ALTER TABLE` statement:
```sql
ALTER TABLE table_name
ADD column_name datatype constraints;
```
13. How can you define a primary key
when creating a table in SQL Server?
You can
define a primary key using the `PRIMARY KEY` constraint within the `CREATE
TABLE` statement:
```sql
CREATE TABLE table_name (
column1 datatype PRIMARY KEY,
column2 datatype,
...
);
```
14. What is the `IDENTITY` property
used for in SQL Server?
The
`IDENTITY` property is used with a numeric column to automatically generate a
unique value for each new row added to the table.
15. How do you create an index in
SQL Server?
To create
an index on a column for faster data retrieval, use the `CREATE INDEX`
statement:
```sql
CREATE INDEX index_name ON table_name
(column_name);
```
16. Explain the concept of foreign
keys in SQL Server.
In SQL
Server, foreign keys establish a relationship between two tables, where the
column with a foreign key references the primary key of another table.
17. What is the difference between
`INNER JOIN` and `LEFT JOIN` in SQL Server?
`INNER
JOIN` returns only the rows that have matching values in both tables, while
`LEFT JOIN` returns all rows from the left table and the matched rows from the
right table.
18. How can you perform a backup and
restore in SQL Server?
To perform
a backup, you can use SQL Server Management Studio (SSMS) or T-SQL commands
like `BACKUP DATABASE`, and to restore the backup, use `RESTORE DATABASE`.
19. What is the purpose of the
`HAVING` clause in SQL Server?
The
`HAVING` clause is used to filter the results of aggregate functions in a
`GROUP BY` query, similar to the `WHERE` clause for individual rows.
20. How do you drop a table in SQL
Server?
To drop a
table and remove it from the database, use the `DROP TABLE` statement:
```sql
DROP TABLE table_name;
```
Above are few top Microsoft SQL Server interview questions. Remember to prepare and expand on these answers.
Good luck with your interview! 👍
0 Comments
Please share your comments ! Thank you !