A (probably very simple) manipulation of a WP database... help needed

[richardfrank]

Hi

 

It's ten years since I dabbled in php and mysql, but I have a problem with a Wordpress site that I look after for a friend which I think could be solved in five minutes of mysql... but it's far too long ago for me to remember how.

 

So...

 

I have an absolutely standard WP database and my task is to take a standard entry in post_content and extract some of it to go into post_excerpt.

 

A typical post_content looks like this:

 

[tab name=The Case]I saw this cat, with similar lesions in both eyes but comfortable and visually still, as a "Have a look at this while you are here" freebee examination in a clinic a few days ago. What are you seeing here?<a href="http://davidlwilliams.org.uk/wp-content/uploads/archivesite/pic523.jpg"><img class="aligncenter size-medium wp-image-532" title="© David Williams" src="http://davidlwilliams.org.uk/wp-content/uploads/archivesite/pic523.jpg" alt="" width="300" height="210" /></a>[/tab][tab name=David's view]This is lipid deposition with associated blood vessels probably after a corneal ulcer. We'd call this a lipid keratopathy, though I've never seen one in a cat before and can't find a report of it in the literature. Not enough money, or a calm enough cat, to take a blood sample for lipid analysis I'm afraid, but as the cat is happy no treatment is needed. If it were maybe the driver of this truck I passed on the way home from the consultation would be able to help!<a href="http://davidlwilliams.org.uk/wp-content/uploads/archivesite/pic524.jpg"><img class="aligncenter size-medium wp-image-532" title="© David Williams" src="http://davidlwilliams.org.uk/wp-content/uploads/archivesite/pic524.jpg" alt="" width="300" height="210" /></a>[/tab][end_tabset]

 

I want to get rid of the first shortcode (i.e. everything between the opening [ ] and then extract the next 20 words... add on a "..." and put it into the post_excerpt field.

 

Probably not difficult... but it is for me ten years on (and feeling decidedly middle-aged)!

 

ALSO, what's the best method for trying a solution out without potentially trashing a database?

 

Would hugely appreciate any help.

 

Richard

[QuickOldCar]

You already have a field with the content, I wouldn't make another in the database or even make another query.

 

You can use post_content() with preg_match and some regex or a string replace afterwards, then limit the words.

There also exists the_excerpt() wordpress function which uses the first 55 words.

 

The best option is to make a plugin or a function in the themes function.php file.

add_filter( 'the_excerpt', 'remove_tab_excerpt' );

function remove_tab_excerpt( $excerpt ) {
    
	return preg_replace ('/\[tab[^\]]*\](.*)\[\/tab\]/', '$1', $excerpt);

}

If you want to do this just posts and not on single pages.

if(!is_single($post)) {
add_filter( 'the_excerpt', 'remove_tab_excerpt' );

function remove_tab_excerpt( $excerpt ) {
    
    return preg_replace ('/\[tab[^\]]*\](.*)\[\/tab\]/', '$1', $excerpt);

}
}

Usually when modifying wordpress is best to make a plugin or a custom theme with functions, when you update anything in wordpress can lose your changes.