过滤mysql搜索的文本

Question

I am new to regex and really don't have a clue. I have a MySql table looking like this:

id | grade | subject | kind | tally
1  | 11    | M       | L    | 1
2  | 11    | E       | L    | 3
3  | 11    | D       | G    | 1
4  | 11    | GK      | G    | 1
5  | 11    | SPA     | G    | 6

you get the idea...:)

Grade is an int, either 11,12 or 13. Subject is a string, between 1-4 "chars" long. Kind is either "L" or "G". Tally is an int, between 1 and 6.

This table is supposed to hold all of the classes/lessons there are at my school. When you write out the classname it would look something like this "11EL4" or "11ML1".

I want to be able to turn this "description" into grade, subject, kind and tally. For example:

function descriptionToArray($description){
    // $grade   = regex voodoo :)
    // $subject = regex voodoo :)
    // ...

    return array("grade"=>$grade,"subject"=>$subject,...);
}

My guess would have been regex but I really don't know how that works (even after tutorials)

Answer 1

Try this:

if (preg_match('/(11|12|13)([A-Z]{1-4})(L|G)([1-6]{1})/', $class_string, $match)) {
    list($dummy, $grade, $subject, $kind, $tally) = $match;
}

Explanation:

• (11|12|13) matches 11, 12 or 13
• ([A-Z]+?) matches 1 or more capital letters (ungreedy)
• (L|G) matches an L or a G
• ([1-6]{1}) matches a single digit in the range 1-6

The $dummy is required because $match[0] will hold the entire regular expression match. Elements 1-4 will hold each patenthesised substring.