Description
DELETE removes rows which satisfy the WHERE
clause from the specified table.
If the condition (WHERE clause) is absent,
the effect is to delete all rows in the table.
The result is a valid, but empty table.
Tip: TRUNCATE is a
PostgreSQL extension which provides a
faster mechanism to remove all rows from a table.
By default DELETE will delete tuples in the table specified
and all its sub-tables. If you wish to only update the
specific table mentioned, you should use the ONLY clause.
You must have write access to the table in order to modify
it, as well as read access to any table whose values are
read in the condition.
Usage
Remove all films but musicals:
DELETE FROM films WHERE kind <> 'Musical';
SELECT * FROM films;
code | title | did | date_prod | kind | len
-------+---------------------------+-----+------------+---------+-------
UA501 | West Side Story | 105 | 1961-01-03 | Musical | 02:32
TC901 | The King and I | 109 | 1956-08-11 | Musical | 02:13
WD101 | Bed Knobs and Broomsticks | 111 | | Musical | 01:57
(3 rows)
Clear the table films:
DELETE FROM films;
SELECT * FROM films;
code | title | did | date_prod | kind | len
------+-------+-----+-----------+------+-----
(0 rows)
