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 AND operator (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	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

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 Date FROM Store_Information
INTERSECT
SELECT Date FROM Internet_Sales

Result:

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