                     ----------  Create or Drop View  ----------

"create view" ޥɤϡŪʥơ֥оΥơ֥Υӥ塼뤿
 "select command" ѷȤޤӥ塼ϥǡ١¸ղ
Ūʥơ֥ǤϤޤ󤬡̤Υơ֥Ʊ褦˰
ޤ
ΥޥɤˤϻĤμबޤ

[ʸ]

a) create view VIEW [(ATTR_NAME {, ATTR_NAME})] as
        select [    |all     |  | *             |]
                    |distinct|  |EXPR {, EXPR}  |
        from TABLE [ [alias] ALIASNAME ] {, TABLE [ [alias] ALIASNAME ]}
        [ WHERE_CLAUSE ]
        [ GROUP_BY_CLAUSE ]
        [ HAVING_CLAUSE ]
        [ SORT_CLAUSE ];

VIEW ϥ "table" դƤʤǤդơ֥̾Ǥꡢ
ATTR_NAME ϥӥ塼°̾Ǥ

[ʸ]

b) create view VIEW as
   select [     |all      | |  *                                           |]
                |distinct | |EXPR [print HEADER]  {, EXPR [print HEADER]}  |
        from TABLE [ [alias] ALIASNAME ] {, TABLE [ [alias] ALIASNAME ]}
        [ WHERE_CLAUSE ]
        [ GROUP_BY_CLAUSE ]
        [ HAVING_CLAUSE ]
        [ SORT_CLAUSE ];

HEADER ˤϡӥ塼ɽ°ղä륿ȥǤޤ

ӥ塼 SELECT ʬϴؿ (max,avg ʤ)  "group by", HAVING
ޤळȤϤǤޤ󡣤ޤ WHERE 黻ҤҲޤ༰ĤȤ
Ǥޤ

[ʸ]:

c) create view VIEW [(ATTR_NAME {, ATTR_NAME})] as

          QUERY_EXPRESSION

          [ SORT_CLAUSE ];

SORT_CLAUSE:

    |sort | [|by|] |ATTR_NAME | [|ascending |] {, |ATTR_NAME | [|ascending |]}
    |order|  |on|  |ATTR_NUM  |  |asc       |     |ATTR_NUM  |  |asc       |
                   |COLUMN_NUM|  |descending|     |COLUMN_NUM|  |descending|
                                 |desc      |                   |desc      |

ܤ SELECT  QUERY_EXPRESSION 򻲾ȤƲ

"drop view" ޥɤϡӥ塼˻Ѥޤ

ιʸ

     drop view VIEW;
