Re: Q:Table designing issue?

Again thanks for showing me possible solutions.

Regards, Xuening Sun

In article <974233576.16676.1.nnrp-14.9e984b29_at_news.demon.co.uk>,   "Jonathan Lewis" <jonathan_at_jlcomp.demon.co.uk> wrote:
> With reference to the previous post,
> you shouldn't use LONGs in Oracle 8,
> these have been superseded by BLOBs
> and CLOBs.
>
> Alternatively, you don't seem to have an
> identifier for each element of the type, but
> how about:
>
> create table assets (
> id number primary key,
> flags number,
> comment varchar2(256)
> );
>
> create table a_type (
> id number references assets,
> attribute1 char(1),
> attribute2 char(1),
> attribute3 char(1),
> attribute4 char(1)
> );
>
> create table b_type(
> id number reference assets,
> rate1 number,
> rate2 number
> )
>
> create table c_type (
> id number references assets,
> attribute5har(1),
> attribute6char(1),
> attribute7char(1),
> attribute8char(1)
> );
>
> Many other details and options to consider and
> fill in. In particular there is no limit on the number
> of structs associated with each asset.
>
> Alternatively, for an object approach:
>
> create type a_row as object(
> attribute1 char(1),
> attribute2 char(1),
> attribute3 char(1),
> attribute4 char(1)
> );
>
> create type a_table as varray(26) of a_row;
>
> similar code for b_row, b_table, c_row, c_table;
> then
>
> create table assets (
> a_struct a_table,
> b_struct b_table,
> c_struct c_table,
> flags number,
> comment varchar(256)
> );
>
> -- actually 'comment' is a reserved word in Oracle.
>
> On the whole I prefer the relational approach to
> the object-like approach, but for a small database
> the object-like approach might be friendlier for
> your front-end coders.
>
> --
>
> Jonathan Lewis
> Yet another Oracle-related web site: http://www.jlcomp.demon.co.uk
>
> Practical Oracle 8i: Building Efficient Databases
>
> Publishers: Addison Wesley Longman
> Book bound date: 8th Dec 2000
> See a first review at:
> http://www.ixora.com.au/resources/index.htm#practical_8i
>
> Xuening Sun wrote in message ...
> >Hi,
> >
> > I was given a flat file which contains metadata about multimedia
 objects
> >(video, audio,
> >image and text). The file structure is created in C using nested
> >"struct". I was
> >asked to create new tables in Oracle database and to move the
 metadata
> >from the
> >flat file into the tables. So applications can retrieve the meta-data
> >directly from
> >a database. The structure within the flat file looks like
> >
> >struct {
> >
> > struct {
> > unsigned char attribute1;
> > unsigned char attribute2;
> > unsigned char attribute3;
> > unsigned char attribute4;
> > } A[26];
> >
> > struct {
> > unsigned long rate1;
> > unsigned long rate2;
> > } B[10];
> >
> > struct {
> > unsigned char attribute5;
> > unsigned char attribute6;
> > unsigned char attribute7;
> > unsigned char attribute8;
> > } C[20];
> >
> > unsigned char flag;
> > char comments[256];
> > } asset;
> >
> >My question is: how do I convert the above file structures to a
 table(s)?
> >
> >
> >Many thanks
> >
> >
> >Xuening Sun
> >
> >
> >
> >--
>
>

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Before you buy. Received on Wed Nov 15 2000 - 11:09:37 CST