Re: Multi-dimensional Array

Consider a creating a record type of the exact columns you need. In effect it will be your multi-dimensional array when you combo that with your other arrays.

On Sun, 23 Mar 2003 17:00:50 +0800, "M" <someone_at_microsoft.com> wrote:

>Thanks. But I do have a problem in using this because:
>(1) I need to have a multi-dimensional array up to 12 parameters; and
>(2) It's not easy to proof that the mapping function is 1-to-1.
>
>Thanks.
>
>"Ed Prochak" <edprochak_at_adelphia.net> wrote in message
>news:3E7B6418.9060100_at_adelphia.net...
>> M wrote:
>> > pl/sql table is only single-dimension. for example,
>> >
>> > declare
>> > type score_type is table of number(3) index by binary_integer;
>> > my_score score_type;
>> > begin
>> > for a in 1 .. 100 loop
>> > my_score(a) := a;
>> > end loop;
>> > end;
>> >
>> > Then I can assign values to my_score(a), a single-dimension array. Just
>> > want to know if there is something like, e.g. 2-dimensional arrays like
>> > my_score(a, b) ... or even multi-dimensional.
>> >
>> > M.
>> >
>> > "Jim Kennedy" <kennedy-downwithspammersfamily_at_attbi.com> wrote in
>message
>> > news:U1lda.141918$S_4.82850_at_rwcrnsc53...
>> >
>> >>How about using pl/sql tables?
>> >>Jim
>> >>"M" <someone_at_microsoft.com> wrote in message
>> >>news:b53ej3$2144$1_at_news.hgc.com.hk...
>> >>
>> >>>Hi all,
>> >>>
>> >>>Just want to know in Oracle 8i, can I define some multi-dimensional
>> >>
>> > array
>> >
>> >>to
>> >>
>> >>>store data for analysis purpose. Can this kind of array be define on
>> >>
>> > the
>> >
>> >>>fly, instead of some objects in the database?
>> >>>
>> >>>Thx.
>> >>>M.
>> >>>
>> >>>
>> >>
>> >>
>> >>
>> >
>> >
>>
>>
>> A google search for "two dimensional array" brings up an article I've
>posted
>> before. But here we go again, you can simulate a two dimensional array
>with a
>> simple mapping function. It's usually what your compiler does when you use
>a
>> multidimensional array in languages that support it. So no need for nested
>> types and tables.
>>
>> ----- INDEX2D
>> ----- GIVEN THE INDICES IN A 2-DIMENSIONAL ARRAY.
>> ----- THIS RETURNS A UNIQUE INDEX IN A LINEAR ARRAY.
>> -----
>> ----- Ed Prochak
>> ----- Magic Interface, Ltd.
>> ----- 440-498-3702
>> -----
>> CREATE OR REPLACE FUNCTION INDEX2D ( A INTEGER, B INTEGER )
>> RETURN INTEGER
>> AS
>> K INTEGER;
>> N INTEGER;
>> NDX INTEGER;
>> BEGIN
>> K := A+B-1;
>> N := K*(K+1);
>> N := N/2;
>> NDX := N+1-B;
>> RETURN NDX;
>> END;
>> /
>>
>> The above routine assumes the first entry in the table is
>> location (1,1) in the 2-D array and location 1 in the linear array.
>> It also assumes use of only positive integers. If you prefer
>> your 2-D array to start at location (0,0), then simply add 1
>> to both parameters before calling this routine OR adjust the body
>> as follows:
>> BEGIN
>> K := A+B+1;
>> N := K*(K+1);
>> N := N/2;
>> NDX := N-B;
>> RETURN NDX;
>> END;
>>
>> Feature: This is an unlimited 2-D array, well suited for use
>> with PL/SQL tables. So don't forget to check that the entry
>> exists at a given location before retrieving it.
>>
>> So you use this within you PL/SQL code for example:
>>
>> DECLARE
>> TYPE EJP_TABLE IS TABLE OF VARCHAR2(30)
>> INDEX BY BINARY_INTEGER;
>> LYNEAR EJP_TABLE;
>> BEGIN
>> LYNEAR(2):='TWO'; --- IT REALLY IS A LINEAR ARRAY
>> LYNEAR(INDEX2D(1,2)):='xxx'; --- but INDEX2D allows you to pretend
>it's 2D
>> LYNEAR(INDEX2D(2,2)):='YYY';
>> LYNEAR(INDEX2D(3,5)):='ZZZ'; --- GREAT FOR SPARSE MATRICES TOO.
>>
>> DBMS_OUTPUT.PUT_LINE('@(2) = '|| LYNEAR(2) );
>> DBMS_OUTPUT.PUT_LINE('@(1,2)) = '||LYNEAR(INDEX2D(1,2))||
>> ' @'||INDEX2D(1,2) );
>> DBMS_OUTPUT.PUT_LINE('@(2,2)) = '||LYNEAR(INDEX2D(2,2))||
>> ' @'||INDEX2D(2,2) );
>> DBMS_OUTPUT.PUT_LINE('@(3,5)) = '||LYNEAR(INDEX2D(3,5))||
>> ' @'||INDEX2D(3,5) );
>> END;
>> /
>>
>> There is an obvious limit on using this function, ie
>> you have to use it whenever you use the array.
>>
>> Not a built in feature of PL/SQL, but very flexible none-the-less.
>>
>>
>> It can be extended to multiple demensions. You just need to do the math.
>>
>> HTH
>> Ed
>>
>>
>> --
>> Ed Prochak
>> running: http://www.faqs.org/faqs/running-faq/
>> family: http://web.magicinterface.com/~collins
>> --
>> "Two roads diverged in a wood and I
>> I took the one less travelled by
>> and that has made all the difference."
>> robert frost
>>
>
Received on Sun Mar 23 2003 - 07:54:13 CST