3.6. The DELETE Command

Earlier in the chapter, we saw that the DELETE command can be used to remove all rows of a table. In this section we revisit the powerful DELETE. Keep in mind as you read this that the DELETE statement can affect multiple rows as we have seen and hence, one must be careful when using it. Following is the general syntax of the DELETE command used to delete rows from a table:

DELETE FROM Table
WHERE (condition)

(condition) determines which rows of the table will be deleted. As you saw earlier, if no WHERE condition is used, all the rows of the table will be deleted.

Multiple rows can be affected by the DELETE command, so be careful when using it.

Here is an example of using the DELETE command on our original Employee table:

DELETE FROM Employee
WHERE salary < 1500

Now if you type:

SELECT *
FROM EMPLOYEE

You will get the following four rows of output:

names                address              employee_number salary
-------------------- -------------------- --------------- ------------
Joe Smith            123 4th St.          101             2500.00
Pradeep Saha         27 Shillingford      103             3300.00
Joya Das             23 Pesterfield Cr    114             2290.00
Terry Livingstone    465 Easter Ave       95              3390.00
 
(4 row(s) affected)