store_namesalesdate Los Angeles$1500jan-05-1999 San Francisco$300jan-08-1999 Boston$700jan-08-1999
Geography 表格
region_namestore_name EastBoston EastNew York WestLos Angeles WestSan Diego
我们就可以用以下的指令来建一个包括每个地区 (region) 销售额 (sales) 的视观表:
CREATE VIEW V_REGION_SALES AS SELECT A1.region_name REGION, SUM(A2.Sales) SALES FROM Geography A1, Store_Information A2 WHERE A1.store_name = A2.store_name GROUP BY A1.region_name