SQL DISTINCT.

DISTINCT in the SELECT Statement

• DISTINCT is used for eliminating duplicate rows.
  DISTINCT included within the SELECT Statement Syntax:

  SELECT [ALL | DISTINCT] select_list
    FROM table/view_list
    [WHERE search_conditions]
    [ORDER BY order_by_list ]

• DISTINCT works on columns value combinations from select_list.
  Example:

  MySQL, Oracle, SQL server, PostgreSQL:

  select DISTINCT ISBN_no "ISBN"
    from order_books
    where Isbn_no like '%8'
    OR Isbn_no like '0%'
    AND item_qty*PRICE < 100
    order by ISBN_no DESC;

  The result should be:

  ISBN
  0764579088
  0764557599
  0672325764
  0471777781
  0201703092