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DELETE(7)                        SQL Commands                        DELETE(7)

NAME
       DELETE - delete rows of a table

SYNOPSIS
       DELETE FROM [ ONLY ] table [ * ] [ [ AS ] alias ]
           [ USING usinglist ]
           [ 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 [truncate(7)] 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.

       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
       table  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.

       usinglist
              A list of table expressions, allowing columns from other tables
              to appear in the WHERE condition. This is similar to the list of
              tables that can be specified in the FROM Clause [select(7)] of a
              SELECT statement; for example, an alias for the table name can
              be specified. Do not repeat the target table in the usinglist,
              unless you wish to set up a self-join.

       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 [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 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. If count is 0, no rows matched
       the condition (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.

SQL - Language Statements         2014-07-21                         DELETE(7)