DBMS SQL Alias ~ GNIITHELP

SQL Alias

Alias is used to give an alias name to a table or a column. This is quite useful in case of large or complex queries. Alias is mainly used for giving a short alias name for a column or a table with complex names.

Syntax of Alias for table names,

SELECT column-name 
from table-name
as alias-name

Following is an Example using Alias,

SELECT * from Employee_detail as ed;

Alias syntax for columns will be like,

SELECT 
column-name as alias-name 
from
table-name

Example using alias for columns,

SELECT customer_id as cid from Emp;

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Example of Alias in SQL Query

Consider the following two tables,

The class table,

ID	Name
1	abhi
2	adam
3	alex
4	anu
5	ashish

The class_info table,

ID	Address
1	DELHI
2	MUMBAI
3	CHENNAI
7	NOIDA
8	PANIPAT

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

SELECT C.id, C.Name, Ci.Address from Class as C, Class_info as Ci where C.id=Ci.id;

Result table look like,

ID	Name	Address
1	abhi	DELHI
2	adam	MUMBAI
3	alex	CHENNAI