SQL Server - FUNCTIONS, OPERATORS and ALIAS WITH SELECT Statement

 

MIN() function returns the smallest value of the selected column.

SELECT Min(EmpId)
FROM Employee

WHERE City= ‘Delhi’;

MAX() function returns the largest value of the selected column.

SELECT Max(EmpId)
FROM Employee

WHERE City= ‘Delhi’;

 

COUNT() function returns the number of rows that matches a specific condition

SELECT Count(EmpId)
FROM Employee

WHERE City= ‘Delhi’;

 

AVG() function returns the average value of a numeric column. 

SELECT Avg(Salary)
FROM Employee

WHERE City= ‘Delhi’;

 

SUM() function returns the total sum of a numeric column

SELECT Sum(Salary)
FROM Employee

WHERE City= ‘Delhi’;

IN Operator

IN operator allows you to specify multiple values in a WHERE clause

SELECT *
FROM Employee

WHERE City IN (‘Delhi’,’Mumbai’;

 

BETWEEN operator

BETWEEN operator selects values within a given range. The values can be numbers, text, or dates.

SELECT *
FROM Employee

WHERE EmpId BETWEEN 50 AND 100;

SQL aliases

SQL aliases are used to give a table or a column a temporary name.

Field name can identified or used by its alias name within the query

SELECT  EmpId AS Id, Name AS Nm,
FROM Employee A

WHERE EmpId >= 100;