ORACLE 11g中的表值函数? (参数化视图) [英] Table-Valued Functions in ORACLE 11g ? ( parameterized views )

问题描述

过去，我已经看到有关此问题的讨论，例如

I've seen discussions about this in the past, such as here. But I'm wondering if somewhere along the line, maybe 10g or 11g (we are using 11g), ORACLE has introduced any better support for "parameterized views", without needing to litter the database with all sorts of user-defined types and/or cursor definitions or sys_context variables all over.

我希望ORACLE可以为一些简单的可以正常使用"的东西增加支持，如T-SQL中的以下示例所示:

I'm hoping maybe ORACLE's added support for something that simply "just works", as per the following example in T-SQL:

CREATE FUNCTION [dbo].[getSomeData] (@PRODID ROWID)  
RETURNS TABLE AS  
    RETURN SELECT PRODID, A, B, C, D, E  
    FROM MY_TABLE  
    WHERE PRODID = @PRODID

然后就这样选择它:

SELECT * FROM dbo.getSomeData(23)

推荐答案

无需SYS_CONTEXT或游标定义. 您确实需要一种类型，以便在解析SQL时可以确定将要返回的列. 也就是说，您可以轻松编写一个脚本，该脚本将根据user_tab_columns中的数据为一个或多个表生成类型和集合类型定义.

No need for SYS_CONTEXT or cursor definitions. You do need a type so that, when the SQL is parsed, it can determine which columns are going to be returned. That said, you can easily write a script that will generate type and collection type definitions for one or more tables based on the data in user_tab_columns.

最近的是

create table my_table
(prodid number, a varchar2(1), b varchar2(1), 
  c varchar2(1), d varchar2(1), e varchar2(1));

create type my_tab_type is object
(prodid number, a varchar2(1), b varchar2(1), 
  c varchar2(1), d varchar2(1), e varchar2(1))
.
/

create type my_tab_type_coll is table of my_tab_type;
/

create or replace function get_some_data (p_val in number) 
return my_tab_type_coll pipelined is
begin
  FOR i in (select * from my_table where prodid=p_val) loop
    pipe row(my_tab_type(i.prodid,i.a,i.b,i.c,i.d,i.e));
  end loop;
  return;
end;
/

SELECT * FROM table(get_Some_Data(3));

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