Provided by: postgresql-client-8.0_8.0.7-2build1_i386
DELETE - delete rows of a table
DELETE FROM [ ONLY ] table [ WHERE condition ]
DELETE deletes rows that satisfy the WHERE clause from the specified
table. If the WHERE clause is absent, the effect is to delete all rows
in the table. The result is a valid, but empty table.
Tip: TRUNCATE [truncate(7)] is a PostgreSQL extension that
provides a faster mechanism to remove all rows from a table.
By default, DELETE will delete rows in the specified table and all its
subtables. If you wish to delete only from the specific table
mentioned, you must use the ONLY clause.
You must have the DELETE privilege on the table to delete from it, as
well as the SELECT privilege for any table whose values are read in the
table The name (optionally schema-qualified) of an existing table.
A value expression that returns a value of type boolean that
determines the rows which are to be deleted.
On successful completion, a DELETE command returns a command tag of the
The count is the number of rows deleted. If count is 0, no rows matched
the condition (this is not considered an error).
PostgreSQL lets you reference columns of other tables in the WHERE
condition. For example, to delete all films produced by a given
producer, one might do
DELETE FROM films
WHERE producer_id = producers.id AND producers.name = ’foo’;
What is essentially happening here is a join between films and
producers, with all successfully joined films rows being marked for
deletion. This syntax is not standard. A more standard way to do it is
DELETE FROM films
WHERE producer_id IN (SELECT id FROM producers WHERE name = ’foo’);
In some cases the join style is easier to write or faster to execute
than the sub-select style. One objection to the join style is that
there is no explicit list of what tables are being used, which makes
the style somewhat error-prone; also it cannot handle self-joins.
Delete all films but musicals:
DELETE FROM films WHERE kind <> ’Musical’;
Clear the table films:
DELETE FROM films;
This command conforms to the SQL standard, except that the ability to
reference other tables in the WHERE clause is a PostgreSQL extension.