Php Mysql Xml

seanmayhew

Im not sure I quite understand XML my basic understanding of it is that its really a supercharged css. Thats my take on it anyway. So is it a good or bad idea to use these three in combination? I picked up a book called "php4 xml" that has a couple of examples in it regarding a calendar that pulls info from a mysql database and formats it with xml. But I've also seen texts that refer to XML as a stand in for MySQL. Help! I'm sorry if these seem like dumb questions but my mother always said theres no such thing as a dumb question.

IS IT A GOOD IDEA TO USE THESE THREE IN COMBINATION OR NOT? Should I just stick to PHP and MySql and just learn a little XML for reference or should I just dive right in to XML and assume I'm going to be able to use it with my PHP scripts that pull from a MySql database?

eoghain

I can't tell you what to do, but I can clear up your ideas about XML.

XML is a Markup Language, just like HTML (HTML is in fact a subset of XML, which is in itself a subset of SGML). However unlike HTML XML allows you the freedom to generate your own HTML like "languages" XML isn't constrained like HTML is so it is more flexable.

Many people are now comming out and saying that XML should be used for data transmission (i.e. taking something from one database to another). While this is a fine notion, it's only real use is when you want to desiminate information to many clients that you don't know. In my oppinion using XML as a data file is just wrong, the XML just adds bloat to your data and something that would only be 1 Meg in a flat file could end up being 1 Gig or larger in XML.

I think that XML is great for things like properties files that are human readable. Or for transmitting small datasets over the internet for display on a local client. But to use them to store data instead of a database is just wrong. Mainly because of you won't get any of the benefits of the database, like indexes.

Knowing XML is a good thing, but knowing SQL, PHP, Database Design are better.

daveyboy

XML is not at all like CSS: quite the opposite. It is about storing data, without formatting. You more or less build your own Markup to suit whatever data you want to store: if you want to build an address book, you use tags like <name> <address> <phoneno> etc. In this respect, it's more flexible that a database - there's no reason why you can't have 2 or more <address> entries if the address is very long, or many <email>s. You can also just use a ready made XML standard, like DocBook or XHTML. The main purpose of XML is to give you the ability to store arbitrary data in a format readable to everyone. In this respect, you can replace a database with XML files, but even with XPATH, you don't have a fraction of the power or speed.

To format XML files, you can just use a PHP parser - Expat or similar - to parse the data from the file and display it as HTML or XHTML. You might want XML if you need to produce several different forms of output - one for browsers, one for PDAs, RTF files etc. Then you use XSLT stylesheets to format your XML. This way you totally seperate data (XML) from logic (PHP) and output (XSLT).

MYSQL -> XML -> HTML is probably a bit OTT, if you only need a website - XSLT is bloody complicated compared to most PHP templating systems and HTML. You would only need to consider XML if you intend to format the same data in lots of different ways, or let other people have access to your raw data, e.g. RSS headline feeds. It is certainly a lot easier to build a site around a database rather than XML.

seanmayhew

Thank you both for helping clear that up.

Because of your comments I will be sticking to PHP and MySQL for my personal stuff and free lance work.

However I work for a newspaper and will be using XML in no time Our Systems Admin is somewhat of a Network Nazi there will be no PHP at work I will be using ASP with essentially no database access and using XSLT. Im really iritated with being stuck with ASP what I consider a dying technology with the current surge of PHP. (Unless of course Microsoft elects to try to kill PHP as well) 😉

_SuperString

On all the projects I have worked on so far, I would'nt touch XML, why complicate things.
I have spent some time learning XML and lots of other things that go along with it, and it does have it uses, but I hav'nt required them as yet.

BuzzLY

I don't think of XML that way. You don't use XML files to store the data like a database. You use it to "package" the data you are sending to be displayed. For instance:

Suppose I had a bunch of recipes. The data is stored in MySQL in a database, and might have several tables. In any case, when I display that information on my website, I can do whatever I want with proprietary queries.

However, suppose I want my recipes to be standardized, so that people using any type of browser could read the recipe -- Even those with cell phones or Palm Pilots. In this case, when a request is made for a recipe, my PHP server gets the data, packages it up with XML tags, and sends it on its way.

Now, when it reaches the destination, It can be displayed in whatever manner makes sense for the medium. In a web browser, I might have a picture of the dish. On a Palm Pilot, it might be in a format that can be used in a shopping list program.

I can still use it however I like on my personal website, but since it's packaged in a certain way with XML, others can use it as well.

Think of it this way: MySQL is the warehouse. XML is the box the merchandise goes in. PHP (and ASP, etc) is the method of shipment(FedEx or UPS), and the browser is the person at the other end that receives the package, opens it, and uses the contents however he sees fit.

Sure, you could just package up all of your merchandise in boxes (XML) if you want, but it's not efficient. It's better to have the items on shelves, where they are easily sorted, accessed, and assembled prior to packaging. XML is NOT a substitute for a database storage system.

Make sense?

BuzzLY

LOL... I just realized I responded to a thread 9 months old. Now why did it show up as a new post in General Help? Damn these polls!!!

_theworks

well it doesnt matter you made a good point where it was needed 🙂 XML rulez for
universal usage 😃😃