DELETE(7)                         PostgreSQL 12.3 Documentation                         DELETE(7)



NAME
       DELETE - delete rows of a table

SYNOPSIS
       [ 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 ] [, ...] ]

DESCRIPTION
       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(7) 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.

       The optional 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 SELECT.

       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 condition.

PARAMETERS
       with_query
           The WITH clause allows you to specify one or more subqueries that can be referenced by
           name in the DELETE query. See Section 7.8 and SELECT(7) for details.

       table_name
           The name (optionally schema-qualified) of the table to delete rows from. If ONLY is
           specified before the table name, matching rows are deleted from the named table only.
           If ONLY is 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.

       alias
           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 DELETE statement must refer to this table as f not foo.

       from_item
           A table expression allowing columns from other tables to appear in the WHERE
           condition. This uses the same syntax as the FROM Clause of a SELECT statement; for
           example, an alias for the table name can be specified. Do not repeat the target table
           as a from_item unless you wish to set up a self-join (in which case it must appear
           with an alias in the from_item).

       condition
           An expression that returns a value of type boolean. Only rows for which this
           expression returns true will be deleted.

       cursor_name
           The name of the cursor to use in a WHERE CURRENT OF condition. 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 OF cannot be specified
           together with a Boolean condition. See DECLARE(7) for more information about using
           cursors with WHERE CURRENT OF.

       output_expression
           An expression to be computed and returned by the DELETE command after each row is
           deleted. The expression can use any column names of the table named by table_name or
           table(s) listed in USING. Write * to return all columns.

       output_name
           A name to use for a returned column.

OUTPUTS
       On successful completion, a DELETE command returns a command tag of the form

           DELETE count

       The 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).

       If the 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.

NOTES
       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 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.

EXAMPLES
       Delete all films but musicals:

           DELETE FROM films WHERE kind <> 'Musical';

       Clear the table films:

           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;

COMPATIBILITY
       This command conforms to the SQL standard, except that the USING and RETURNING clauses are
       PostgreSQL extensions, as is the ability to use WITH with DELETE.

SEE ALSO
       TRUNCATE(7)



PostgreSQL 12.3                                2020                                     DELETE(7)