In Oracle, INTERSECT Operator is used to return the results of 2 or more SELECT statement. It picks the common or intersecting records from compound SELECT queries

Syntax

SELECT expression1, expression2, ... expression_n  
FROM table1  
WHERE conditions  
INTERSECT  
SELECT expression1, expression2, ... expression_n  
FROM table2  
WHERE conditions;  

Parameters

1- expression1, expression2, ... expression_n: It specifies the columns that you want to retrieve

2- table1, table2: It specifies the tables that you want to retrieve records from

3- conditions: it specifies the conditions that must be fulfilled for the records to be selected

Oracle INTERSECT Example: (with single expression)

Suppliers Table

Suppliers Data

Order_details Table

Order_details Data

SELECT supplier_id  
FROM suppliers  
INTERSECT  
SELECT supplier_id  
FROM order_details;  

In the above example, the supplier_id appears in both the suppliers and order_details table. Now the common entries will be returned in the result set

Output

Oracle INTERSECT Example: (with multiple expressions)

Supplier Table

Supplier Data

Customer Table

Customer Data

SELECT supplier_id, last_name, first_name  
FROM supplier  
WHERE first_name <> 'dhirubhai'  
INTERSECT  
SELECT customer_id, last_name, first_name  
FROM customer  
WHERE customer_id < 5;  

Output

The above example returns the records from the supplier table where the supplier_id, last_name and first_name values match the customer_id, last_name, and first_name value of customer table