DELETE — delete rows of a table
[ WITH [ RECURSIVE ]
with_query[, ...] ] DELETE FROM [ ONLY ]
table_name[ * ] [ [ AS ]
alias] [ USING
from_item[, ...] ] [ WHERE
condition| WHERE CURRENT OF
cursor_name] [ RETURNING * |
output_expression[ [ AS ]
output_name] [, ...] ]
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.
TRUNCATE is a PostgreSQL extension that 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
USING clause. Which technique is more appropriate depends on the specific circumstances.
RETURNING clause causes
DELETE 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
USING, can be computed. The syntax of the
RETURNING list is identical to that of the output list of
You must have the
DELETE privilege on the table to delete from it, as well as the
SELECT privilege for any table in the
USING clause or whose values are read in the
WITHclause allows you to specify one or more subqueries that can be referenced by name in the
DELETEquery. See Section 7.8 and SELECT for details.
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 table expression allowing columns from other tables to appear in the
WHEREcondition. This uses the same syntax as the
FROMClause of a
SELECTstatement; for example, an alias for the table name can be specified. Do not repeat the target table as a
from_itemunless you wish to set up a self-join (in which case it must appear with an alias in the
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
DELETE command returns a command tag of the form
count is the number of rows deleted. Note that the number may be less than the number of rows that matched the
condition when deletes were suppressed by a
BEFORE DELETE trigger. If
count is 0, no rows were deleted by the query (this is not considered an error).
DELETE command contains a
RETURNING clause, the result will be similar to that of a
SELECT statement containing the columns and values defined in the
RETURNING list, computed over the row(s) deleted by the command.
PostgreSQL lets you reference columns of other tables in the
WHERE condition by specifying the other tables in the
USING 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
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.
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
tasks on which the cursor
c_tasks is currently positioned:
DELETE FROM tasks WHERE CURRENT OF c_tasks;
This command conforms to the SQL standard, except that the
RETURNING clauses are PostgreSQL extensions, as is the ability to use