I'm extending the $wpdb object with properties for my custom tables.

function setup_wpdb()
    global $wpdb;

    // Create properties for custom tables
    $wpdb->my_plugin_table1 = $wpdb->prefix.'my_plugin_table1';
    $wpdb->my_plugin_table2 = $wpdb->prefix.'my_plugin_table2';

Is this a good practice? I guess as long as the properties are prefixed with the plugin name, it should be fine. Defining a constant may work too. What do you prefer and why? Thanks.

1 Answer 1


As long as...

  1. You use $wpdb->prefix (or $wpdb->base_prefix) to prefix the table
  2. Your table name is someplace public, and easily available for other plugins, themes and end users to use and extend

I would say either setting the table as a property on $wpdb or using a constant is fine. If you choose to use $wpdb be aware that another plugin (or theme or whatever) can just overwrite your property in the same way you set it. For that reason, it's a bit more "safe" to use something like a constant.

Also, always carefully question whether or not you need to add a table.

I tend to use constants, but if I'm doing something like creating a termmeta table, then I would use a $wpdb property.

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