Array confusion

bizshop

I'm hopelessly confused on arrays. I query a database and it pulls, for instance,

'ISBN','authorname','title' for all books in 'romance' category

There may be 20 books. I know how to get them all to list, one after the other, but how do I get just the information for one particular title over and over again without multiple queries to the database?

Reason is that I might want to list the books and data in various orders on the page. If I want to put data matching ISBN #3 first and ISBN #2 second and ISBN #4 third, etc.....

I know I can do it with a WHERE query in mysql but it seems I should be able to avoid multiple queries to db....

Anon

I dont quite get what you mean? if you want to order your results you could always use a where, group, order by commands, but I find it's more simple if I use a for statement and echo the results other than doing a for or while statement to put them into arrays, and then trying to sort the array and echoing it. get me?

cordex

An example using MySQL syntax. I don't know your table name so I replaced it with tblBooks. This code is similar to what Rulian suggested.

$sel_st = "SELECT ISBN, authorname,title FROM tblBooks WHERE Category='romance' ORDER BY ISBN";
$sel_rs = mysql_query($sel_st);
echo "Category: romance ";
while($sel_ar = fetch_array($sel_rs))
{
echo "ISBN: ".$sel_ar[ISBN] ." ";
echo "Title: ". $sel_ar[title] ." ";
echo "Author: ". $sel_ar[author] ." ";
}

Does that do what you're looking for?

bizshop

Actually the opposite - my problem is how to be able to use the data in an unordered way.

HTML page designed by client may have product pictures on them already, I need to fit the mysql data to each for a cart system - but the items are not in any particular order on the page (other than all being from the same category)

In other words, first item on page might have ISBN 2, second ISBN 1, third ISBN 4, etc.

The select SELECT ISBN, authorname,title FROM tblBooks WHERE Category='romance returns all as I understand it, and the 'while' deals with each array in sequence (first book array found, second array etc) - but I want to pull the data out of sequence.

Sorry for not being clear..

factory21

Well, if you want to avoid multiple queries, you could download the database into a PHP array keyed off of something unique such as the ISBN number.

something like:
SELECT * from books WHERE category='romance';

while ($row=mysql_fetch_assoc($result))
$books[$row["isbn"]]=$row;

Then, just access the data via $books[$isbn];