sql建立视图步骤（SQL 创建、更新和删除视图的方法）

CREATE VIEW view_name AS
SELECT column_name(s)
FROM table_name
WHERE condition

CREATE VIEW [Current Product List] AS
SELECT ProductID,ProductName
FROM Products
WHERE Discontinued=No

SELECT * FROM [Current Product List]

CREATE VIEW [Products Above Average Price] AS
SELECT ProductName,UnitPrice
FROM Products
WHERE UnitPrice>(SELECT AVG(UnitPrice) FROM Products)

SELECT * FROM [Products Above Average Price]

CREATE VIEW [Category Sales For 1997] AS
SELECT DISTINCT CategoryName,Sum(ProductSales) AS CategorySales
FROM [Product Sales for 1997]
GROUP BY CategoryName

SELECT * FROM [Category Sales For 1997]

SELECT * FROM [Category Sales For 1997]
WHERE CategoryName='Beverages'

CREATE OR REPLACE VIEW view_name AS
SELECT column_name(s)
FROM table_name
WHERE condition

CREATE VIEW [Current Product List] AS
SELECT ProductID,ProductName,Category
FROM Products
WHERE Discontinued=No

ALTER VIEW [ schema_name . ] view_name [ ( column [ ,...n ] ) ] 
[ WITH <view_attribute> [ ,...n ] ] 
AS select_statement 
[ WITH CHECK OPTION ] [ ; ]

<view_attribute> ::= 
{ 
  [ ENCRYPTION ]
  [ SCHEMABINDING ]
  [ VIEW_METADATA ]   
} 

DROP VIEW view_name