Re: Arrays ... need clarification....

Medi Montaseri wrote:
> I can use some clarification on Array usage....
>
> Given the following definition....
>
> create table test ( name varchar(20) , grades integer[]);
>
> How do I insert a new record, I see multiple ways of doing it but if one
> does
> not do this right, then updates will fail....

I think this is probably a misuse of arrays. You might better model this
as something like:

create table student (
  student_id serial primary key,
  name text
);
create table test (
  test_id serial primary key,
  date_taken timestamp,
  description text
);
create table grade (
  grade_id serial primary key,
  test_id int references test,
  student_id int references student,
  test_grade int
);

Now you can do something like:
select s.name, avg(g.test_grade), stddev(g.test_grade) as average from
student s, test t, grade g where s.student_id = g.student_id and
g.test_id = t.test_id and t.date_taken between '01-01-2003' and
'03-31-2003' group by s.name;

But in any case, see:
http://www.postgresql.org/docs/view.php?version=7.3&idoc=1&file=arrays.html
for more information on use of arrays.

Joe