pl/sql中定义和调用存储过程

Question

create or replace procedure a_time
is
begin
dbms_session.set_nls('nls_date_format','''yyyy-mm-dd''');
dbms_output.put_line(sysdate);
end;SQL> exec a_time;
F8运行 出现
Compilation errors for PROCEDURE SYSTEM.A_TIMEError: PLS-00103: 出现符号 "SQL"
Line: 8
Text: SQL> exec a_time;
初学者不明白，希望各位不吝赐教

Answer 1

scott@SZTYORA> create or replace procedure a_time
  2  is
  3  begin
  4  dbms_session.set_nls('nls_date_format','''yyyy-mm-dd''');
  5  dbms_output.put_line(sysdate);
  6  end;
  7  /过程已创建。已用时间:  00: 00: 00.42
scott@SZTYORA> exec a_time;
2010-07-06PL/SQL 过程已成功完成。已用时间:  00: 00: 00.01
scott@SZTYORA>

Answer 2

create or replace procedure a_time
is
begin
dbms_session.set_nls('nls_date_format','''yyyy-mm-dd''');
dbms_output.put_line(sysdate);
end;
/

Answer 3

create or replace procedure a_time
is
begin
dbms_session.set_nls('nls_date_format','''yyyy-mm-dd''');
dbms_output.put_line(sysdate);
end;
/
没有问题

Answer 4

SQL> 
SQL> create or replace procedure a_time
  2  is
  3  begin
  4  dbms_session.set_nls('nls_date_format','''yyyy-mm-dd''');
  5  dbms_output.put_line(sysdate);
  6  end;
  7  /
 
Procedure created
 
SQL> exec a_time;
 
PL/SQL procedure successfully completed为什么没有时间显示

Answer 5

SQL> set serveroutput on
谢谢各位