Interactive SQL Tutorial

10. Adding, deleting, updating data

Adding Data

To insert rows into a table, do the following:

INSERT INTO ANTIQUES VALUES (21, 01, 'Ottoman', 200.00)

This inserts the data into the table, as a new row, column-by-column, in the pre-defined order. Instead, let's change the order and leave Price blank:

INSERT INTO ANTIQUES (BUYERID, SELLERID, ITEM)

VALUES (01, 21, 'Ottoman')

Deleting Data

Let's delete this new row back out of the database:

DELETE FROM ANTIQUES

WHERE ITEM = 'Ottoman'

But if there is another row that contains 'Ottoman', that row will be deleted also. Let's delete all rows (one, in this case) that contain the specific data we added before:

DELETE FROM ANTIQUES

WHERE ITEM = 'Ottoman' AND BUYERID = 01 AND SELLERID = 21

Updating Data

Let's update a Price into a row that doesn't have a price listed yet:

UPDATE ANTIQUES SET PRICE = 500.00 WHERE ITEM = 'Chair'

This sets all Chair's Prices to 500.00. As shown above, more WHERE conditionals, using AND, must be used to limit the updating to more specific rows. Also, additional columns may be set by separating equal statements with commas.

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