从Oracle函数返回多个值

时间:2019-07-08 13:21:52

标签: sql oracle plsql set-returning-functions

我想创建一个将多行返回到对象类型表中的函数。

我已经创建了一个对象和一个嵌套表对象,现在当我运行该函数时,出现错误提示

PL / SQL:忽略了SQL语句 PL / SQL:ORA-00947:值不足

-- Object type creation
create or replace type test_object_sn as object
(
    column_1 varchar2(30),
    column_2 varchar2(30),
    column_3 number 
);


-- Table of object
create or replace type test_otable_sn as table of test_object_sn; 

-- function (where I get an error)
create or replace function load_test_object_sn
return test_otable_sn
as  
    details test_otable_sn;
begin
    with ad as (select 'a', 'b', 4   from dual
    union all 
    select 'r', '5', 3  from dual
    union all
    select 'g', 's', 3  from dual)
    select * into details from ad; 

    return details;
end;

我想用数据加载test_otable_sn表对象,然后通过我的load_test_object_sn函数使用table()函数查询它 例如select * from table(load_test_object_sn);

1 个答案:

答案 0 :(得分:1)

更新:

  

您知道如何针对我有一条sql的情况修改此设置吗?   包含在字符串变量中的语句要执行?

是的,我们可以使用游标引用(SYS_REFCURSOR)和OPEN / FETCH / CLOSE代替CURSOR和CURSOR FOR LOOP。

语法为OPEN <cursor-reference> FOR <string-containing-sql-statement>。见下文。

CREATE OR REPLACE FUNCTION load_test_object_sn
RETURN test_otable_sn
AS  
  details test_otable_sn := test_otable_sn();

  -- Variable stores SQL statement for cursor
  l_sql CLOB :=
    q'[with ad as (
         select 'a' column_1, 'b' column_2, 4 column_3 from dual union all
         select 'r', '5', 3  from dual union all 
         select 'g', 's', 3  from dual
       )
       select *
         from ad]';

  -- Cursor reference allows us to open cursor for SQL statement above
  rc SYS_REFCURSOR;

  -- Define object instance to store each row fetched from the cursor
  l_obj test_object_sn := test_object_sn(NULL, NULL, NULL);

  i PLS_INTEGER := 1;
BEGIN

  -- Explicitly open, fetch from, and close the cursor
  OPEN rc FOR l_sql;
  LOOP
    FETCH rc INTO l_obj.column_1, l_obj.column_2, l_obj.column_3;
    EXIT WHEN rc%NOTFOUND;
    details.extend();
    details(i) := test_object_sn(l_obj.column_1, l_obj.column_2, l_obj.column_3);
    i := i + 1;
  END LOOP;
  CLOSE rc;

  RETURN details;
END;

原始答案:

不幸的是,不能以这种方式对集合使用SELECT * INTO,因此这是填充表的另一种方法:

create or replace function load_test_object_sn
return test_otable_sn
as  
    details test_otable_sn := test_otable_sn();
    cursor c_ad is
    with ad as (select 'a' column_1, 'b' column_2, 4 column_3   from dual
    union all 
    select 'r', '5', 3  from dual
    union all
    select 'g', 's', 3  from dual)
    select * from ad;
    i pls_integer := 1;

begin

   for ad_rec in c_ad loop     
      details.extend();
      details(i) := test_object_sn(ad_rec.column_1, ad_rec.column_2, ad_rec.column_3);
      i := i + 1;
   end loop;

    return details;
end;
/

输出:

SQL> SELECT * FROM TABLE(load_test_object_sn);

COLUMN_1   COLUMN_2     COLUMN_3
---------- ---------- ----------
a          b                   4
r          5                   3
g          s                   3