redhat man page for delete

DELETE(7)							   SQL Commands 							 DELETE(7)

NAME
       DELETE - delete rows of a table

SYNOPSIS
       DELETE FROM [ ONLY ] table [ WHERE condition ]

   INPUTS
       table  The name (optionally schema-qualified) of an existing table.

       condition
	      This is an SQL selection query which returns the rows which are to be deleted.

	      Refer to the SELECT statement for further description of the WHERE clause.

   OUTPUTS
       DELETE count
	      Message returned if items are successfully deleted. The count is the number of rows deleted.

	      If count is 0, no rows were deleted.

DESCRIPTION
       DELETE removes rows which satisfy the WHERE clause from the specified table.

       If the condition (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 which provides a faster mechanism to remove all rows from a table.

       By  default  DELETE  will  delete  tuples in the table specified and all its sub-tables. If you wish to only update the specific table men-
       tioned, you should use the ONLY clause.

       You must have write access to the table in order to modify it, as well as read access to any table whose values are read in the condition.

USAGE
       Remove all films but musicals:

       DELETE FROM films WHERE kind <> 'Musical';
       SELECT * FROM films;

	code  | 	  title 	  | did | date_prod  |	kind   | len
       -------+---------------------------+-----+------------+---------+-------
	UA501 | West Side Story 	  | 105 | 1961-01-03 | Musical | 02:32
	TC901 | The King and I		  | 109 | 1956-08-11 | Musical | 02:13
	WD101 | Bed Knobs and Broomsticks | 111 |	     | Musical | 01:57
       (3 rows)

       Clear the table films:

       DELETE FROM films;
       SELECT * FROM films;

	code | title | did | date_prod | kind | len
       ------+-------+-----+-----------+------+-----
       (0 rows)

COMPATIBILITY
   SQL92
       SQL92 allows a positioned DELETE statement:

       DELETE FROM table WHERE
	   CURRENT OF cursor

       where cursor identifies an open cursor.	Interactive cursors in PostgreSQL are read-only.

SQL - Language Statements					    2002-11-22								 DELETE(7)