【ocp-12c】最新Oracle OCP-071考试题库（44题）

标签：out   null   missing   state   use   忽略   _id   sele   tab   

View the Exhibit and examine the details of the ORDER_ITEMS table.

Evaluate the following SQL statements:

Statement 1:

SELECT MAX(unit_price*quantity) "Maximum Order"

FROM order_items;

Statement 2:

SELECT MAX(unit_price*quantity) "Maximum Order"

FROM order_items

GROUP BY order_id;

Which statements are true regarding the output of these SQL statements? (Choose all that apply.)

A) Both statements would ignore NULL values for the UNIT_PRICE and QUANTITY columns.

B) Statement 1 would return only one row of output.

C) Both the statements would give the same output.

D) Statement 2 would return multiple rows of output.

E) Statement 1 would not return any row because the GROUP BY clause is missing.

Anser：ABD

(解析：对于 null 值，Oracle 计算的时候结果为空，但是在求最大值的时候，会忽略)

SQL> select sal*comm from emp;

SAL*COMM

480000

625000

1750000

…

SQL> select max(sal*comm) from emp;

MAX(SAL*COMM)

1750000

【ocp-12c】最新Oracle OCP-071考试题库（44题）

标签：out   null   missing   state   use   忽略   _id   sele   tab   

原文地址：https://blog.51cto.com/13854012/2355482