EQUI JOIN

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Oracle - Equi Join

Oracle Equi join returns the matching column values of the associated tables. It uses a comparison operator in the WHERE clause to refer equality.

Syntax :

SELECT column_list   
FROM table1, table2....  
WHERE table1.column_name =  
table2.column_name;  

Equijoin also can be performed by using JOIN keyword followed by ON keyword and then specifying names of the columns along with their associated tables to check equality.

Syntax :

SELECT *  
FROM table1   
JOIN table2  
[ON (join_condition)]   

Oracle EQUI JOIN Example

Let' take two tables "agents" and "customer".

Agents table :

AGENT_ID	AGENT_NAME	AGENT_CITY
3	Ajay	Ahmedabad
7	Nirupam	London
11	Teja	Mumbai

Customers table :

CUSTOMER_ID	FIRST_NAME	LAST_NAME
1	Neha	Ullal
2	Richa	Kohli
3	Swetha	Pandit
4	Jansi	Kapoor

Execute this query

SELECT agents.agent_city,customer.last_name,    
customer.first_name   
FROM agents,customer    
WHERE agents.agent_id=customer.customer_id;    

Output :

AGENT_CITY	FIRST_NAME	LAST_NAME
Ahmedabad	Swetha	Pandit