SQL Tutorial

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:

Date

Jan-07-1999

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