2011-11-4 LEAST函数

http://www.itpub.net/thread-1499223-12-1.html

113楼

下面的选项都实现了这个过程：

CREATE OR REPLACE PROCEDURE plch_show_lowest (   number1_in   IN NUMBER, number2_in   IN NUMBER, number3_in   IN NUMBER)IS

哪一种能够显示传入的三个数中最小的一个？假设传给plch_show_lowest的实际值都不为空。

(A)

BEGIN   DBMS_OUTPUT.put_line (      LEAST (number1_in, LEAST (number2_in, number3_in)));END;

(B)

BEGIN   DBMS_OUTPUT.put_line (      SMALLEST (number1_in, number2_in, number3_in));END;

(C)

BEGIN   DBMS_OUTPUT.put_line (      MIN (number1_in, number2_in, number3_in));END;

(D)

   l_lowest   NUMBER;BEGIN   SELECT LEAST (number1_in, number2_in, number3_in)     INTO l_lowest     FROM DUAL;   DBMS_OUTPUT.put_line (l_lowest);END;

(E)

   l_lowest   NUMBER := number1_in;BEGIN   IF number2_in < l_lowest   THEN      l_lowest := number2_in;   END IF;   IF number3_in < l_lowest   THEN      l_lowest := number3_in;   END IF;   DBMS_OUTPUT.put_line (l_lowest);END;

(F)

BEGIN   DBMS_OUTPUT.put_line (      LEAST (number1_in, number2_in, number3_in));END;

实测

B报错 PLS-00201: 必须声明标识符 'SMALLEST'

C报错 PLS-00103: 出现符号 ")"在需要下列之一时： := . ( % ; 符号 "(" 被替换为 ")" 后继续。

ADEF均正确