Microsoft SQL Server Tutorials

SQL - Sub Query Examples

Sub Query Examples in SQL Server 

Write a query to find the details of employee who is earning the highest salary.

select * from tab2 where Salary=(select MAX(salary) from tab2)

Write a query to find the details of employee who is earning second highest salary. 

select * from tab2 where Salary=(select MAX(salary)from tab2 where Salary<(select MAX(salary) from tab2))

Write a query to find the details of employee who is earning third highest salary.

select * from tab2 where Salary=(select MAX(salary)from tab2 where Salary<(select MAX(salary) from tab2 where Salary <(select MAX(salary) from tab2)))

How find first and last record from table row in SQL one query?

Use below query for select first record in table.

SELECT * FROM EMP WHERE EID = (SELECT Min (EID) FROM EMP)
 

Use below query for select Last record in table.

SELECT * FROM EMP WHERE EID = (SELECT Max (EID) FROM EMP)

 

Syntax to Find Any Position Record From A table

SELECT * FROM(SELECT * ,ROW_NUMBER() OVER (ORDER BY empid) AS RowNum FROM Employeeemployee WHERE RowNum=15

 

Syntax to Delete Duplicate Records from a table contains more than two same duplicate values

SIDSNAMEFEErownum
10Sai120001
20Siddhu450001
30Meena650001
30Meena650002
30Meena650003
30Meena650004
30Meena650005

with duplicates as

(select * ,ROW_NUMBER() over(partition by sid,sname, fee order by sid,sname,fee) rownum from student)

delete from duplicates where rownum 1

select the complete above query and execute then we delete all duplicate records which are greater than 1 i.e.output is like below

SIDSNAMEFEErownum
10Sai120001
20Siddhu450001
30Meena650001

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Microsoft SQL Server

Beginner 5 Hours

Sub Query Examples in SQL Server 

Write a query to find the details of employee who is earning the highest salary.

select * from tab2 where Salary=(select MAX(salary) from tab2)

Write a query to find the details of employee who is earning second highest salary. 

select * from tab2 where Salary=(select MAX(salary)from tab2 where Salary<(select MAX(salary) from tab2))

Write a query to find the details of employee who is earning third highest salary.

select * from tab2 where Salary=(select MAX(salary)from tab2 where Salary<(select MAX(salary) from tab2 where Salary <(select MAX(salary) from tab2)))

How find first and last record from table row in SQL one query?

Use below query for select first record in table.

SELECT * FROM EMP WHERE EID = (SELECT Min (EID) FROM EMP)
 

Use below query for select Last record in table.

SELECT * FROM EMP WHERE EID = (SELECT Max (EID) FROM EMP)

 

Syntax to Find Any Position Record From A table

SELECT * FROM(SELECT * ,ROW_NUMBER() OVER (ORDER BY empid) AS RowNum FROM Employeeemployee WHERE RowNum=15

 

Syntax to Delete Duplicate Records from a table contains more than two same duplicate values

SIDSNAMEFEErownum
10Sai120001
20Siddhu450001
30Meena650001
30Meena650002
30Meena650003
30Meena650004
30Meena650005

with duplicates as

(select * ,ROW_NUMBER() over(partition by sid,sname, fee order by sid,sname,fee) rownum from student)

delete from duplicates where rownum 1

select the complete above query and execute then we delete all duplicate records which are greater than 1 i.e.output is like below

SIDSNAMEFEErownum
10Sai120001
20Siddhu450001
30Meena650001

Related Tutorials

Frequently Asked Questions for Microsoft SQL Server

To install Microsoft MySQL Server on Windows, you need to download the installer from the official MySQL website. Follow the on-screen instructions to complete the installation process and set up the server.

To upgrade MySQL Server, download the latest version from the official site, run the installer, and follow the upgrade instructions. Backup your data before starting the process.

You can integrate MySQL Server with web applications written in languages like PHP, Node.js, and Python by using the appropriate MySQL connector libraries.<

Stored procedures are precompiled SQL statements that can be executed repeatedly. They improve performance by reducing the amount of SQL code sent to the server.

The MySQL root user is the default administrator account with full privileges. To secure it, ensure strong password protection, disable remote access, and grant minimal permissions.

Microsoft MySQL Server is an open-source relational database management system (RDBMS) that provides high-performance data storage and retrieval. It is often used for web applications and other data-driven platforms.

The default username for Microsoft MySQL Server is "root". During the installation process, you'll set a password. If you forget it, you can reset the MySQL root password using the command line.

Common MySQL error codes include 1045 (Access Denied), 1062 (Duplicate Entry), and 2002 (Can't Connect to MySQL Server).

Some advantages include its high availability, scalability, open-source nature, and the support of a large community of developers. Microsoft MySQL Server is also compatible with various platforms and provides advanced data security features.

The MySQL query cache stores the result of SELECT queries to speed up response times for identical queries. You can enable it in the MySQL configuration file.

InnoDB supports ACID-compliant transactions, foreign keys, and row-level locking, making it more suitable for high-concurrency environments. MyISAM is faster for read-heavy operations but lacks transaction support.

You can manage users in MySQL using the CREATE USER, GRANT, and REVOKE commands to set permissions for specific users.

To configure Microsoft MySQL Server, you need to access the MySQL Configuration File (my.ini) and make necessary adjustments like setting up users, enabling ports, and optimizing server performance.

You can use the SHOW STATUS and SHOW VARIABLES commands to monitor MySQL performance. Alternatively, use tools like MySQL Workbench and Percona Monitoring and Management (PMM).

To optimize MySQL Server performance, you can tweak configuration settings like innodb_buffer_pool_size, query_cache_size, and tmp_table_size. Indexing and query optimization also play a crucial role.

The primary difference is that MySQL is open-source and cross-platform, while SQL Server is a proprietary product by Microsoft that primarily runs on Windows. MySQL is more popular in the open-source community, while SQL Server is used in enterprise environments.

To repair a corrupt table, you can use the REPAIR TABLE command in MySQL:

REPAIR TABLE table_name;

If you're facing MySQL connectivity issues, ensure that the MySQL service is running, the port is open, and your firewall settings are correctly configured.

You can import data into MySQL using the LOAD DATA INFILE command or by using tools like phpMyAdmin or MySQL Workbench.

To enable foreign keys, ensure your tables use the InnoDB storage engine. Then, define the FOREIGN KEY constraint in your table creation statement.

To check the version, simply open the command prompt or terminal and type:

mysql --version

This will return the current version of Microsoft MySQL Server installed on your system.

MySQL data types define the type of data a column can store. Some common types include VARCHAR, INT, DATE, TEXT, and BLOB.

To create a new database, use the following SQL command:

CREATE DATABASE database_name;

You can back up a MySQL Server database using the mysqldump command. For example:

mysqldump -u username -p database_name > backup_file.sql

Yes, Microsoft MySQL Server can run on various platforms, including Linux, Windows, and macOS, making it a versatile choice for developers.

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