SQL Tutorial

The MINUS operates on two SQL statements. It takes all the results from the first SQL statement, and then subtract out the ones that are present in the second SQL statement to get the final answer. If the second SQL statement includes results not present in the first SQL statement, such results are ignored.

The syntax is as follows:

[SQL Statement 1]
MINUS
[SQL Statement 2]

Let's continue with the same example:

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 store sales, but no internet sales. To do so, we use the following SQL statement:

SELECT Date FROM Store_Information
MINUS
SELECT Date FROM Internet_Sales

Result:

Date

Jan-05-1999

Jan-08-1999

"Jan-05-1999", "Jan-07-1999", and "Jan-08-1999" are the distinct values returned from "SELECT Date FROM Store_Information." "Jan-07-1999" is also returned from the second SQL statement, "SELECT Date FROM Internet_Sales," so it is excluded from the final result set.

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