Dev Chunks

Take Regular Backups

Carey — Sun, 19 Aug 2007 21:34:08 +0000

This is advice that you will have heard 1000 times before, and will probably be just about to stop reading it… but please, for your sake, ensure that you have proper backups in place. As you well know, all our work and effort can dissapear with unbelievable ease. Knock that Monday morning cup of coffee over [...]

Incorrect usage of UNION and ORDER BY

Carey — Thu, 16 Aug 2007 21:13:25 +0000

A common problem when using the UNION command in MySQL is when you want to order the sets of data differently. If you do it incorrectly, you will see the error message: Incorrect usage of UNION and ORDER BY To solve the problem, wrap each individual SELECT statement in parenthesis as follows: (SELECT col1,col2,col3 FROM table1) UNION (SELECT cola,colb,colc FROM [...]

Using the PHP Modulus Operator

Carey — Sun, 05 Aug 2007 21:42:49 +0000

The modulus operator is very useful and quite often not known by many new developers. To best describe what it does, I will give an example of where it is useful. First imaging you are looping through an array of monkeys and want to highlight every third monkey in bold. This is how it is done [...]

Use PHP to Capitalise Your Text

Carey — Tue, 31 Jul 2007 20:25:20 +0000

If you want to make sure your text is nicely formatted there are a couple of tricks using PHP that can help you. Changing the case of your words is one useful feature, that can be achieved with the functions in the following example. echo strtoupper('abc'); # outputs: ABC echo strtolower('ABC'); # outputs: abc echo ucfirst('frogs eat dogs.'); # [...]

Keep Your Website Hidden While Testing

Carey — Fri, 27 Jul 2007 10:06:18 +0000

This is a little trick I use a lot. Quite often I am working on a website for a client that has an admin area. I like to give access to the admin area while I am still working on the front end design. This way the client can start adding products/content/whatever while I am building [...]

subquery workaround in MySQL 4

Carey — Tue, 24 Jul 2007 15:31:04 +0000

One of the most useful additions to MySQL 5 is the subquery, which lets you execute sql like this: SELECT username FROM users WHERE user_id IN (SELECT user_id FROM admins); Unfortunately, MySQL 4 is lacking this feature and is still prevalent in many web hosts. If you have a need to use a subquery, try this following [...]

explode() and implode() php arrays

Carey — Mon, 23 Jul 2007 15:30:09 +0000

No this isn’t about getting frustrated with PHP and nuking your server, this is a couple of very useful (although hard to remember) array functions. explode() will take a string and give you an array, splitting that string on the delimiter you give. For example, if you have a list of comma seperated values you will [...]

Dump your PHP Variables with var_dump()

Carey — Sun, 22 Jul 2007 19:00:09 +0000

To find out the full details of any given variable in php, simply use var_dump() as follows: var_dump($variable); This will show you the php variable type, its value and if it is an object or array the structure and all information will be explored recursively. The only slight disadvantage to using var_dump() is that the output is sent [...]

MySQL Random Row

Carey — Sun, 01 Jul 2007 23:24:35 +0000

To get a random row from your table, you can use the following trick: SELECT * FROM myTable ORDER BY RAND() LIMIT 1

Struggling to debug php? Enable all errors

Carey — Sun, 27 May 2007 19:18:39 +0000

If you are having a problem debugging any php code a good thing to do is make sure all errors are showing. Simply use the following code at the beginning of your script: error_reporting(E_ALL);You may find that the open source code you are using or the website created by somebody else is hiding too many errors [...]