请教Table()使用方法 select * from table(....)

请教Table()使用方法 select * from table(....)

http://www.itpub.net/thread-276171-1-1.html

http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:2270447621346

 

ORA-22905:无法从非嵌套项访问行 之解决

http://blog.csdn.net/simonezhlx/article/details/3168385

 

You Asked (Jump to Tom's latest followup)

1. Does oracle support calling a procedure as a derived table,
   Eg
   select * from (call myprocedure) ....

2. Also, does it support creation of a view over a procedure ,

   Eg,

   Create view as (call myprocedure)





and we said...

You need to use Oracle9i or up to do that (but I do show a way in 8i):

[email protected]> create or replace function virtual_table( p_num_rows in
number )
  2  return virtual_table_type
  3  PIPELINED -- NOTE the pipelined keyword
  4  is
  5  begin
  6      for i in 1 .. p_num_rows
  7      loop
  8          pipe row( i );
  9      end loop;
10 
11      return; -- note return with no value!
12  end;
13  /

Function created.

[email protected]> [email protected]> [email protected]> set echo
off
Enter to continue

=================================================================


now we'll just see this in action


[email protected]> [email protected]> select * from TABLE(
virtual_table(5) );

COLUMN_VALUE
------------
           1
           2
           3
           4
           5

[email protected]> select * from TABLE( virtual_table(10) );

COLUMN_VALUE
------------
           1
           2
           3
           4
           5
           6
           7
           8
           9
          10

10 rows selected.

We use "pipe" instead of suspend.


Prior to 9i, there is no pipe, it would look like this:


[email protected]> create or replace type virtual_table_type as table of
number
  2  /

Type created.

[email protected]> [email protected]> create or replace function
virtual_table( p_num_rows in
number )
  2  return virtual_table_type
  3  is
  4          l_data virtual_table_type := virtual_table_type();
  5  begin
  6      for i in 1 .. p_num_rows
  7      loop
  8                  l_data.extend;
  9                  l_data(l_data.count) := i;
10      end loop;
11 
12      return l_data;
13  end;
14  /

Function created.

[email protected]> [email protected]> select * from TABLE(
virtual_table(5) );

COLUMN_VALUE
------------
           1
           2
           3
           4
           5

[email protected]> select * from TABLE( virtual_table(10) );

COLUMN_VALUE
------------
           1
           2
           3
           4
           5
           6
           7
           8
           9
          10

10 rows selected.


you would fill up the collect and then return it (no "pipe", no suspend
functionality)


   Reviews     
GOTO a page to Bookmark Review | Bottom | Top
Great answer!!  December 19, 2001
Reviewer:  Jimson K John  from Bangalore, India

This is what I was looking for! Thanks!


GOTO a page to Bookmark Review | Bottom | Top
Interesting  December 20, 2001
Reviewer:  Randy  from CHicago,IL

It sounds very useful. But unfortunately when I try
select * from TABLE(virtual_table(5) ); after finishing previous steps in my
8.1.7 server, I am get
select * from TABLE(virtual_table(5) )
                    *
ERROR at line 1:
ORA-22905: cannot access rows from a non-nested table item

The type and the function was creted successfully.




Followup: 
try:

[email protected]> select * from TABLE( cast ( virtual_table(5)
as virtual_table_type ) );

COLUMN_VALUE
------------
           1
           2
           3
           4
           5


sorry about that -- forgot the CAST which is needed in 8i, but not 9i

上面说，9i 不用加这个cast，不过，最近在开发时有发现在9i 下不加cast也出现ORA-22905错误！！！加了就好了，怪事，呵呵，Linux系统，oracle9204的，有的又不会，真是怪。