如何在程序 oracle 中从 table 随机打印？

Question

假设我有一个 table child 我想在一个过程中 select 从 1 到 5 随机，随机值来自 table 并打印出来。我该怎么做？

create table child(name varchar2(20), age number);

insert into child(name, age) values('A',5);
insert into child(name, age) values('B',12);
insert into child(name, age) values('C',7);
insert into child(name, age) values('D',4);

create or replace procedure random_child
as
 l_name child.name%type;
 l_age child.age%type;
begin
  for i in(select dbms_random.value(1,5) 
           from (select name from child sample(50)))
loop
 DBMS_OUTPUT.put_line(i.name);
end loop;
end;

它给了我一个 PLS-00302：名称必须声明

Answer 1

那里没有i.name；第 6 行末尾缺少别名：

SQL> create or replace procedure random_child
  2  as
  3   l_name child.name%type;
  4   l_age child.age%type;
  5  begin
  6    for i in(select dbms_random.value(1,5)  as name  --> here
  7             from (select name from child sample(50)))
  8  loop
  9   DBMS_OUTPUT.put_line(i.name);
 10  end loop;
 11  end;
 12  /

Procedure created.

SQL> exec random_child
1,30966411991963041689918865935551009464
1,13993832387089615287177388489291237644
3,85292920191145794430114472793297022632

PL/SQL procedure successfully completed.

SQL>

Answer 2

您可以使用：

CREATE PROCEDURE random_child
AS
BEGIN
  FOR i in(
    SELECT name,
           FLOOR(DBMS_RANDOM.VALUE(1,6)) AS value
    FROM   child
    SAMPLE(50)
  )
  LOOP
   DBMS_OUTPUT.put_line(i.name || ' ' || i.value);
  END LOOP;
END;
/

然后：

BEGIN
  random_child();
END;
/

可能随机输出：

B 3
C 2
D 2

db<>fiddle here

如何在程序 oracle 中从 table 随机打印？

How to print random from table in a procedure oracle?

oracle

plsql