念经的时候打钟鼓，这是什么表示？什么意思？

参数的默认值SQL> CREATE OR REPLACE PROCEDURE HelloWorld3 (2 p_user_name VARCHAR2,3 p_val1 VARCHAR2 DEFAULT ' Good Moning,',4 p_val2 VARCHAR2 DEFAULT ' Nice to Meet you'5 ) AS6 BEGIN7 dbms_output.put_line('Hello ' || p_user_name || p_val1 || p_val2 || '!');8 END HelloWorld3;9 /Procedure created.指定参数名称调用此部分使用 “参数默认值”那一小节的存储过程。用于说明当最后2个参数是有默认的时候，如何跳过中间那个。SQL> BEGIN2 HelloWorld3('Edward');3 HelloWorld3('Edward', p_val1 => ' Good Night,');4 HelloWorld3('Edward', p_val1 => ' Good Night,', p_val2 => 'Bye');5 HelloWorld3('Edward', p_val2 => ' HeiHei ');6 END;7 /Hello Edward Good Moning, Nice to Meet you!Hello Edward Good Night, Nice to Meet you!Hello Edward Good Night,Bye!Hello Edward Good Moning, HeiHei !PL/SQL procedure successfully completed.