**Function in SQL Server-**

** ** A function is a set of code that perform specific task. There are some predefined function in SQL Server are as follow-

COUNT(), AVG(), SUM(), MAX(), MIN().

**SQL COUNT(), AVG() and SUM() functions – **

**COUNT() – **

The SQL COUNT () function is used to find the number of rows in a column of a table.

Syntax-

SELECT COUNT(column_ name) FROM table_name WHERE condition;

**AVG() function- **

The SQL AVG() function is used to find the Average of numerical column values of a table.

Syntax-

SELECT AVG(column_name) FROM table_name WHERE condition;

**SUM() function – **

The SQL SUM() function is used to find the sum of numerical column values in a table.

Syntax-

SELECT SUM(column_name) FROM table_name WHERE condition;

We have a database table “TeacherDetails”-

**Example-**

**COUNT()-** The following statement is to find the number of row in a column of ‘TeacherDetails’ table.

** select count(stuCourse) from TeacherData;
**

**AVG()- ** The following statement is to find the Average of numerical column values of ‘TeacherDetails’ table.

** select avg(Salary) from TeacherData;
**

**SUM()-** The following statement is to find the sum of the numerical column values in table ‘TeacherDetails’.

** select sum(Salary) from TeacherData;**

** SQL MIN and MAX – **

The SQL function MIN() and MAX() is to find the minimum and maximum values form database table.

The** MIN()** function is used to find the minimum value from table.

The** MAX()** function is used to find the maximum value from table.

**MIN(** **) **Syntax-

SELECT MIN(column_name) FROM table_name WHERE condition;

**MAX()** Syntax-

SELECT MAX(column_name) FROM table_name WHERE condition; MAX() function

**Example-**

- Let have a table ‘TeacherDetails’.

**MAX()-** Follow the statement to find the maximum value from ‘TeacherDetails’ table.

**select max(Salary) from TeacherData;**

To find the record which has maximum Salary then you can use the following statement.

**select * from TeacherData where Salary=(select max(Salary) from TeacherData); **

**MIN()-** The following statement is used to find the minimum Salary from ‘TeacherDetails’ table.

**select min(Salary) from TeacherData; **

To find the record of that row which has minimum value is like as-

**select * from TeacherData where Salary =(select min(Salary) from TeacherData); **