SQL Alias

sql Alias is used to give an alias name to a column or a table. This is used for giving short name of a column and a table. you have to use alias, when column name is large or you can combine two column in a single column name or more readable.

SELECT * FROM Employee

 Aliases for columns:

SELECT

column-name as alias-name

from

table-name

Example1:

SELECT

  First_name AS [Employee Name]

FROM Employee

Result:

 

In the above query, the column First_name is given a alias as "Employee Name". So when the result is displayed the column name appears as "Employee Name" instead of  'First_name'.

Example2:

SELECT

  First_name + ' '+ Last_name AS [Employee Name]

FROM Employee

Result:

In the above query, the column First_name and Last_name combine together to display a single column as alias as "Employee Name". So when the result is displayed the column name appears as "Employee Name" instead of  "First_name" and "Last_Name". 

Table Name Alias

Syntax:

 

SELECT column-name

from table-name as alias-name

Example1:

Consider Two tables, First is Employee and Second is tblDepartment. 

SELECT

  emp.First_name, emp.Last_name,emp.Salary, emp.Joining_date, Department_ID

FROM Employee emp

 

SELECT dept.Id, dept.Name as [Department Name]

FROM tblDepartment dept

Below is the Query to fetch data from both the tables using SQL Alias,

 

SELECT 

  emp.First_name, emp.Last_name,emp.Salary, emp.Joining_date,

  dept.Name as [Department Name] 

from Employee as emp

INNER JOIN tblDepartment as dept

ON emp.Department_ID=dept.Id

 

Result