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Page Revision: 2012/06/09 09:13
Tricks
This is taken from
wp-hackersScott Merrill wrote:
> Bill Smith wrote:
>
>>1) I'm working on a small plugin that requires an additional database
>>table. Currently I'm using a query like
>>
>>SHOW TABLES LIKE 'wp_mytable'
>
> Here's what I do in my subscribe2 plugin, which uses a custom table:
> ///////////////////////
> function s2_install() {
> // include upgrade-functions for maybe_create_table;
> if (! function_exists('maybe_create_table')) {
> require_once(ABSPATH . '/wp-admin/upgrade-functions.php');
> }
maybe_create_table() also uses SHOW TABLES, which is fine, but doesn't
avoid that query if that's the intent.
Here's what I do:
class MyPlugin {
$table_version = 1;
function MyPlugin() {
$this->settings = get_settings('MyPlugin');
if($this->settings
'table_version' < $this->$table_version)
$this->make_tables();
//These also go here:
// add_action('admin_menu', array(&$this, 'admin_menu'));
}
function make_tables() {
global $table_prefix;
if(!require_once(ABSPATH . 'wp-admin/upgrade-functions.php')) {
die('Foolish plugin has added its own maybe_upgrade* functions');
}
$qry = "CREATE TABLE {$table_prefix}mytable (
mytable_id BIGINT(11) NOT NULL AUTO_INCREMENT,
PRIMARY KEY (mytable_id)
);
";
dbDelta($qry);
$this->settings
'table_version' = $this->table_version;
update_option('MyPlugin', $this->settings);
}
}
$myplugin = new MyPlugin();
What benefit has all this? If you change the table structure in an
upgrade (add a field, change a field type, add an enum value, etc.), you
simply increment the $table_version and the plugin will automatically
upgrade the table. Plus it's one less database hit if the options info
is already cached.