OCP-1Z0-051-V9.02-52题
52. View the Exhibit and examine the structure of the PRODUCTS table.Using the PRODUCTS table,you issue the following query to generate the names, current list price, and discounted list price for all those products whose list price falls below $10 after a discount of 25% isapplied on it.SQL>SELECT prod_name, prod_list_price, prod_list_price - (prod_list_price * .25) "DISCOUNTED_PRICE" FROM products WHERE discounted_price < 10;The query generates an error.What is the reason for the error?A. The parenthesis should be added to enclose the entire expression.B. The double quotation marksshould be removed from the column alias.C. The column alias should be replaced with the expression in the WHERE clause.D. The column alias should be put in uppercase and enclosed with in double quotation marks in theWHERE clause.Answer: C 答案解析：where子句不能跟别名,可以跟表达式 实验验证：scott@TESTDB> select empno,ename,sal+10 "sal10" from emp where sal10<1500;select empno,ename,sal+10 "sal10" from emp where sal10<1500 *ERROR at line 1:ORA-00904: "SAL10": invalid identifierscott@TESTDB> select empno,ename,sal+10 "sal10" from emp where sal+10<1500; EMPNO ENAME sal10---------- ---------- ---------- 7369 SMITH 810 7521 WARD 1260 7654 MARTIN 1260 7876 ADAMS 1110 7900 JAMES 960 7934 MILLER 13106 rows selected. 版权声明：本文为博主原创文章，未经博主允许不得转载。
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