[RESOLVED] if (x != x from row before){do this}

TobyRT

Hi,

I'm trying to format a stocklist of books, there are many and various rules which I can get my head round using if(), but there are two (related) statements which i can't fathom.

If there are 10 different books by 10 different authors, each book (with author) will have a new line. No problem.

The problem is, what if an author has more than 1 book? My remit is to only echo the author name once.

InData (a plugin for InDesign) has the command <<if author like previous author>><<print title>><print price>><<else>><<if author not like previous author<<print title>><<print author>><<print price>>

I was wondering if php had a similar command for what came in the line before it?

Ideally this would be done with a normalised database with a separate author table. Sadly I don't have that luxury - this is coming from a csv file which i'm importing onto my sql server.

Any suggestions please?

toplay

You sort the data by author (in MySQL it's by using the ORDER BY clause).

Then it's just a matter of doing basic logic in PHP while retrieve the data. Example:

// Open, select DB, and do select query

$prev_author = '';  // Initialize to something that wouldn't match the DB data

while ($row = mysql_fetch_assoc($result)) {

if ($prev_author != $row['author']) {
    echo 'Author: ', $row['author'], '<br>'; // Display name once per author
    $prev_author = $row['author'];   // Set to current author
}

// Display other column data here or do whatever

}

Good luck.

TobyRT

I wonder if maybe I didn't explain properly.

Currently I have this:
ISBN1 - Title1 - Author1-Price
ISBN2 - Title2 - Author1-Price
ISBN3 - Title3- Author1-Price

What I want is:
ISBN1 - Title1 - Author1-Price
ISBN2 - Title2 - -Price
ISBN3 - Title3- -Price

That make sense?

The other problem I have is that I can't change the order - it's already sorted correctly (by 6 different fields) when I get it.

toplay

Read my previous post again.

If you want it by author, then it sounds like it's not sorted in the order you want to display it in. The author needs to be sorted before their title. So all the author's books are lumped together first. If you are sorting by ISBN or title first, you could end up with many authors jumbled about. Unless you're saying that even though you show ISBN and title first before the author, it is really coming in by author (all the ISBN and titles happen to be grouped all together for the same author).

You said that it's being inserted into a database. So, you should then be able to sort it any way you desire. Secondly, if it's not going into a database, then it can still be sorted by one of the many sorting functions PHP has.

The example I gave in my previous post is simply reading one record/row at a time and seeing if the author has changed from the previous record that was read. If it's different then display the author. That's what I understood you wanted from your original post here.

Good luck.

TobyRT

Ahh...I see!

Sorry - I somehow managed to misread your code - my apologies!!

That's worked a treat!

Now - just need to work on my style sheets!