#! code

Today I needed to grab some data from a table where there was more than one occurrence of a string within another string. Basically, I needed to find all URL's from a table that were more than 3 levels deep (i.e. with 3 slashes), but realised there wasn't a function to do this in MySQL. I found an alternative method, but it got me thinking on how that might be possible.

As part of debugging a bit of code I needed to know the longest possible field lengths that a record contains. You might need to know this if you are performing a database migration. The following query returns a field, along with the length of the string, and orders the results by the number of characters in that string.

SELECT field, CHARACTER_LENGTH(field) as fieldCharacterCount FROM table ORDER BY fieldCharacterCount DESC

I quite often find myself needing to know how long a string is, especially when testing form validation or when trying to write a page description. I therefore like to have this little tool to help me by simply counting the number of characters in a given string.

Use the JavaScript text length tool here.

Use the following function to pad a string with to a set length with a given string. The function takes three parameters. The string to be padded, the total number of characters that the string must be, and the string to be added. If the third parameter is not given then 0 is used as a default.

I found this very handy function on the php.net site in the user comments for the strlen() function. It accepts a string in ASCII or UTF-8 format and finds out how long that string is in bytes.

The function works by going through the string and adding how many bytes each character represents. For normal ASCII values this is a single byte so 1 is added to the total. Unicode characters can be up to 6 bytes and so the rest of this function works out how many bytes the character takes up by using AND calculations.

If you want to know the length of a string in PHP you would normally turn to the strlen() function which simply tells you the length of the string.

$string = 'this is a string';
$strLength = strlen($string);

To use this to check the length of the string use the following example.