SQL小提琴输出错误

Question

实际上我是PL/SQL的新手

我在SQL Fiddle中使用oracle pl/sql创建了下表

create table Employee(name varchar2(100),id integer, salary integer,PRIMARY KEY(id));
insert into Employee(name,id,salary) values('sa',94,100);
insert into Employee(name,id,salary) values('pr',88,150);
insert into Employee(name,id,salary) values('ji',33,900);
insert into Employee(name,id,salary) values('na',24,880);
insert into Employee(name,id,salary) values('po',65,770);
insert into Employee(name,id,salary) values('ri',69,910);
insert into Employee(name,id,salary) values('uj',12,650);
insert into Employee(name,id,salary) values('ad',43,440);
insert into Employee(name,id,salary) values('sam',40,550);

我执行了以下查询

 DECLARE
 employee_record Employee%ROWTYPE;
 BEGIN
 select * into employee_record from Employee where id>90;
 dbms_output.put_line(employee_record.name||' '||employee_record.id||' '||employee_record.salary);
 END;
 /

我得到以下输出

Record Count: 0; Execution Time: 2ms 

它应该打印员工记录中的值,对吧？我的SQL查询中有什么问题或sql小提琴无法显示dbms_output的一些问题？

Answer 1

你需要模仿dbms_output.put_line:)

架构:

create table Employee(
  name varchar2(100),
  id integer, 
  salary integer,
  PRIMARY KEY(id)
);

insert into Employee(name,id,salary) values('sa',94,100);
insert into Employee(name,id,salary) values('pr',88,150);
insert into Employee(name,id,salary) values('ji',33,900);
insert into Employee(name,id,salary) values('na',24,880);
insert into Employee(name,id,salary) values('po',65,770);
insert into Employee(name,id,salary) values('ri',69,910);
insert into Employee(name,id,salary) values('uj',12,650);
insert into Employee(name,id,salary) values('ad',43,440);
insert into Employee(name,id,salary) values('sam',40,550);

create table dbmsoutput (
  pos int,
  mes varchar2(4000)
);

SQL:

DECLARE
  employee_record Employee%ROWTYPE;
  procedure put_line(p_mes in varchar2) is
     v_pos int; 
  begin  
     select count(0) into v_pos from dbmsoutput;  
     insert into dbmsoutput (pos, mes) values (v_pos, p_mes);
  end;
BEGIN
 put_line('Hello!  This code is powered by dbms_output emulator :)');
 -- Your code here:
 select * into employee_record from Employee where id>90;
 put_line(employee_record.name||' '||employee_record.id||' '||employee_record.salary);
 --
 put_line('Bye!');
END;
/


SELECT mes FROM dbmsoutput order by pos

小提琴

Answer 2

正如好奇心一样,您可以dbms_output从SQL Fiddle 获得有限的结果,但是您需要一个函数来提取缓冲的行并以您可以选择的形式返回它们.这使用了一个流水线表:

create type t_lines as table of varchar2(4000)
/

create or replace function get_lines
return t_lines pipelined is
  lines dbms_output.chararr;
  numlines integer;
begin
  numlines := 999;
  dbms_output.get_lines(lines, numlines);
  if numlines > 0 then
    for i in 1..numlines loop
      pipe row (lines(i));
    end loop;
  else
    pipe row ('No data');
  end if;
end;
/

然后,在你发出任何dbms_output.put_line电话之后:

select * from table(get_lines);

演示.并查看dbms_output文档以了解其get_lines过程的作用以及它与您的put_lines呼叫的关系.

但仅仅因为你可以做某事,并不意味着你一定应该做.这很尴尬,不能扩展,但也没有尝试通过SQL Fiddle学习PL/SQL.

我第二次推荐使用自己的数据库,但我建议你看一下你可以在VirtualBox中运行的预先构建的虚拟机映像,这可以节省你在设置中的大量时间 - 你不需要不得不担心如何安装Oracle软件或创建和配置数据库,它只是随时可以使用,如果出现问题,您可以将其丢弃或轻松重新启动.