Set page template for all pages?

Question

I know the page template is set in the wpdb as meta_key = _wp_page_template and meta_value = template.php.

How can I write a SQL script to set each post where post_type = 'page' to a specific template?

EDIT: Based on the comments below, I'll add the detail that I am wishing to "normalize" my pages since some are set to custom templates.

Answer 1

EDIT As noted in the comments on your question, the best approach would just be to edit your page.php file. If you want ALL of your pages to have the same page template, and not have to do anything extra to set it that way, it's quite obvious why this is a good idea. :)

Then, you can make a custom page template for the pages that you don't use your default page template for. That is pretty much what that system was made for!

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If you insist though:

The page template of each page is actually stored as a custom field, you could loop over each post in your code and set the page template that way, instead of going and doing it in the database manually. See below:

add_action( 'admin_init', 'set_page_templates' );

function set_page_templates(){

    foreach( get_posts('post_type=page&posts_per_page=-1') as $page ) {
        $current_template = get_post_meta( $page->ID, '_wp_page_template', true );
        $new_template = 'new_template.php';

        if( $current_template != $new_template )
            update_post_meta( $page->ID, '_wp_page_template', $new_template );
    }

}

There may be a better action to put this on, as this will run on every admin page load. Maybe you could run this once and then remove the code, it should work fine that way. Alternatively, you could hook it onto the save_post action (which actually will return the page ID you are saving for you as one of your function arguments) to automatically change the page template if it isn't what you want it to be on save of a post or page (of course skipping the foreach in that case).

Answer 2

Without editing anything hardcoded in the php files there is just one simple SQL query to do it all, can be executed in phpMyAdmin:

UPDATE wp_postmeta
SET meta_value = 'default'
WHERE meta_key = '_wp_page_template';

Hope it may help some people!

Answer 3

Another option for setting templates is via the template filters. You can add your own logic to force specific templates under whatever conditions you specify.

function wpd_page_template_filter( $templates = '' ) {

    // the passed $templates contains a single or array of templates that apply to this query

    // get queried page object
    $this_page = get_queried_object();

    // check $this_page meta key, check slug, check parent, etc..

    return locate_template( 'my-custom-template.php' );
}
add_filter( 'page_template', 'wpd_page_template_filter' );