DELETE - delete rows of a table
[ WITH [ RECURSIVE ]
with_query[, ...] ] DELETE FROM [ ONLY ]
table_name[ * ] [ [ AS ]
alias] [ USING
using_list] [ WHERE
condition| WHERE CURRENT OF
cursor_name] [ RETURNING * |
output_expression[ [ AS ]
output_name] [, ...] ]
deletes rows that satisfy the
clause from the specified table. If the
clause is absent, the effect is to delete
all rows in the table. The result is a valid, but empty table.
TRUNCATE provides a faster mechanism to remove all rows from a table.
There are two ways to delete rows in a table using information
contained in other tables in the database: using sub-selects, or
specifying additional tables in the
Which technique is more appropriate depends on the specific
to compute and return value(s) based on each row actually deleted.
Any expression using the table's columns, and/or columns of other
tables mentioned in
, can be computed.
The syntax of the
list is identical to that of the
output list of
You must have the
privilege on the table
to delete from it, as well as the
privilege for any table in the
whose values are read in the
The name (optionally schema-qualified) of the table to delete rows from. If
ONLYis specified before the table name, matching rows are deleted from the named table only. If
ONLYis not specified, matching rows are also deleted from any tables inheriting from the named table. Optionally,
*can be specified after the table name to explicitly indicate that descendant tables are included.
A substitute name for the target table. When an alias is provided, it completely hides the actual name of the table. For example, given
DELETE FROM foo AS f, the remainder of the
DELETEstatement must refer to this table as
A list of table expressions, allowing columns from other tables to appear in the
WHEREcondition. This is similar to the list of tables that can be specified in the
FROMClause of a
SELECTstatement; for example, an alias for the table name can be specified. Do not repeat the target table in the
using_list, unless you wish to set up a self-join.
An expression that returns a value of type
boolean. Only rows for which this expression returns
truewill be deleted.
The name of the cursor to use in a
WHERE CURRENT OFcondition. The row to be deleted is the one most recently fetched from this cursor. The cursor must be a non-grouping query on the
DELETE's target table. Note that
WHERE CURRENT OFcannot be specified together with a Boolean condition. See DECLARE for more information about using cursors with
WHERE CURRENT OF.
An expression to be computed and returned by the
DELETEcommand after each row is deleted. The expression can use any column names of the table named by
table_nameor table(s) listed in
*to return all columns.
A name to use for a returned column.
On successful completion, a
command returns a command
tag of the form
is the number
of rows deleted. Note that the number may be less than the number of
rows that matched the
when deletes were
suppressed by a
is 0, no rows were deleted by
the query (this is not considered an error).
command contains a
clause, the result will be similar to that of a
statement containing the columns and values defined in the
list, computed over the row(s) deleted by the
lets you reference columns of
other tables in the
condition by specifying the
other tables in the
clause. For example,
to delete all films produced by a given producer, one can do:
DELETE FROM films USING producers WHERE producer_id = producers.id AND producers.name = 'foo';
What is essentially happening here is a join between
, with all successfully joined
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.
Delete all films but musicals:
DELETE FROM films WHERE kind <> 'Musical';
Clear the table
DELETE FROM films;
Delete completed tasks, returning full details of the deleted rows:
DELETE FROM tasks WHERE status = 'DONE' RETURNING *;
Delete the row of
on which the cursor
is currently positioned:
DELETE FROM tasks WHERE CURRENT OF c_tasks;
This command conforms to the
extensions, as is the ability