OCP-1Z0-051-V9.02-162题

162. View the Exhibit and examine the structure of the PRODUCTS, SALES, and SALE_SUMMARY

tables.

SALE_VW   is a view created using the following command :

SQL>CREATE VIEW sale_vw AS

SELECT prod_id, SUM(quantity_sold) QTY_SOLD

FROM sales GROUP BY prod_id;

You issue the following command to add a row to the  SALE_SUMMARY   table :

SQL>INSERT INTO sale_summary

SELECT prod_id, prod_name, qty_sold FROM sale_vw JOIN products  

USING (prod_id) WHERE prod_id = 16;

What is the outcome? 

A. It executes successfully.

B. It gives an error because a complex view cannot be used to add data into the SALE_SUMMARY table.

C. It gives an error because the column names in the subquery and the SALE_SUMMARY table do not

match.

D. It gives an error because the number of columns to be inserted does not match with the number of

columns in the SALE_SUMMARY table.

Answer: D

答案解析：

参考：http://blog.csdn.net/rlhua/article/details/12885143

由于列的数量不匹配造成的，如果数量一致，会执行成功。

 带有子查询的INSERT语句，勿使用VALUES子句，并且使INSERT子句中的列数与子查询中的列数匹配。