[allnodcoms]

Originally Posted by JiminSA

a) it doesn't handle a variable number of multiple elements (occurences)

Not with you mate, what are you trying to do?

If you can give me an example I'm sure we can work it out...

Danny

[JiminSA]

When a vehicle in the database has been edited, I would like it to reflect in the record - i.e. by which user and at what time - by including 2 fields "agent" and "date_time", one occurrence for each time it's edited - which can happen n times i.e. a variable number of occurrences in the life of the record.

If SQL can handle that scenario, I'd love to know...

[allnodcoms]

It can James, welcome to the world of database design.

I'd have a separate table called 'edits' or similar, this table has the name and timestamp, maybe a reason for the edit (?) and a reference to the main vehicle table that it refers to. Whenever the vehicle table is edited, you just create a new 'edits' entry and set the pointer to the vehicle entry's id.

Easy peasy!

Danny

[JiminSA]

That can work!
All I need to do is SELECT * FROM editing_table WHERE recid = $row['id'] ORDER BY datestamp
or summat like that...
Then there are no limits on the number of edit transactions! - I like the way you roll Danny!

[allnodcoms]

It's easy when you know how mate...

Danny

[JiminSA]

Danny, is there anything to stop me serialising an array into a row and then un-serialising it?

[allnodcoms]

Er... Why?

Danny

[JiminSA]

That way I could have a variable number of occurrences of items. i.e. by putting arrays into cells, no?

[allnodcoms]

No mate, you can't put arrays into a table. Basically a table is an array. If you want to embed an array into a table you would do as you did with the edited entries: create another table an link each instance back to the parent table with an ID field.

Danny

[JiminSA]

Aha! On the premise that a serialised array is just a data string, I thought it would be possible to put it into a cell and guess what? You can! Check this
Is this a case of the student teaching the mentor? No offense mate

[allnodcoms]

Originally Posted by JiminSA

Is this a case of the student teaching the mentor? No offense mate

Er... No.

Technically the contents of a field is just a string of 1s and 0s, so you can (I repeat for emphasis - technically) put what you like in it. But to go back to my previous reply - Why? You lose the ability to query the data, you'd have to read it in, unpack it, look through it, pack it back up and shoe horn it back in there...

There are far more elegant ways of achieving the exact same thing without the use of power tools or large hammers

Danny

[JiminSA]

There is a valid reason why I would like this facility...

The quick 'n dirty CMS I'm using for this vehicle database originally used this technique (Serialize/Unserialize) for the whole file. I decided that because this db will get very big (4-5 records added daily, ad infinitum) that it was time to go MySql...
Now then, each vehicle entry can have any number of photographs uploaded and associated with it, id's of which are placed in an array within the serialised record.

The CMS photo handling (add/delete/re-order etc.,) is all oriented to an array set up and is fairly complex - hence the desire to have an array within a MySql cell.

Hope that clarifies it a bit, mate and I hope you don't think I was being arrogant in my last entry - I don't pretend that I could teach an old dog like you anything new!!!