SQL Table Alias and Column Alias Syntax and Example

SQL Table and Column Alias
You can give a table or a column another name by using an alias. This can be a good thing to do if you have very long or complex table names or column names.An alias name could be anything, but usually it is short.

SQL Alias Syntax for Tables:
SELECT column_name(s) FROM Table_name Alias_name

SQL Alias Syntax for Columns:
SELECT column_name AS alias_name FROM  Table_name

Example :
Suppose we have a EMP Table as follows :

E_Id	First_Name	Last_Name	Dept_Id	Address	Salary
1001	Ravi	Kumar	1	Hyderabad	20000
1002	David	Smith	2	Bangalore	35000
1003	Victory	Venkatesh	1	Hyderabad	50000
1004	Tamatam	Reddy	3	Bangalore	25000
1005	William	Smith	2	Hyderabad	40000
1006	King	Fisher	6	Bangalore	30000

Now see the following Query with Alias Names for Columns and Table :

Select E.E_Id,E.First_Name as F_Name, E.Last_Name as L_Name 
From EMP E 
WHERE E.Address='Bangalore'

Here :
E is an Alias Table name for EMP
F_Name is an Alias column name for First_Name
L_Name is an Alias column name for Last_Name

Out Put :

E_Id	F_Name	L_Name
1002	David	Smith
1004	Tamatam	Reddy
1006	King	Fisher

Aliases can make queries easier to write and to read.

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