SQL INTERSECT

SQL > Advanced SQL > Intersect

Similar to the UNION command, INTERSECT also operates on two SQL statements. The difference is that, while UNION essentially acts as an OR operator (value is selected if it appears in either the first or the second statement), the INTERSECT command acts as an ANDoperator (value is selected only if it appears in both statements).

The syntax is as follows:

[SQL Statement 1]
INTERSECT
[SQL Statement 2];

Let's assume that we have the following two tables,

Table Store_Information

Store_Name	Sales	Txn_Date
Los Angeles	1500	Jan-05-1999
San Diego	250	Jan-07-1999
Los Angeles	300	Jan-08-1999
Boston	700	Jan-08-1999

Table Internet_Sales

Txn_Date	Sales
Jan-07-1999	250
Jan-10-1999	535
Jan-11-1999	320
Jan-12-1999	750

and we want to find out all the dates where there are both store sales and internet sales. To do so, we use the following SQL statement:

SELECT Txn_Date FROM Store_Information
INTERSECT
SELECT Txn_Date FROM Internet_Sales;

Result:

Txn_Date

Jan-07-1999

Please note that the INTERSECT command will only return distinct values.