9. Deletions

Rows can be removed from a table using the DELETE command. Suppose you are no longer interested in the weather of Hayward. Then you can do the following to delete those rows from the table:

All weather records belonging to Hayward are removed.

     city      | temp_lo | temp_hi | prcp |    date
---------------+---------+---------+------+------------
 San Francisco |      46 |      50 | 0.25 | 1994-11-27
 San Francisco |      41 |      55 |    0 | 1994-11-29
(2 rows)

One should be wary of statements of the form

Without a qualification, DELETE will remove all rows from the given table, leaving it empty. The system will not request confirmation before doing this!