令人惊讶的是，事实并非如此。相反，您需要使用以下函数，该函数在插件激活时运行。

define( \'YOUR_PLUGIN_VERSION\', \'1.0.0\' );

register_activation_hook( __FILE__, \'your_plugin_activation_function\' );

function your_plugin_activation_function() {
  // Do activation tasks here.
  your_install_function();
  your_upgrade_migration_function();
}

function your_install_function() {

  // Set the current version of the plugin in the db.
  update_option( \'your_plugin_version\', YOUR_PLUGIN_VERSION );
}

function your_upgrade_migration_function() {

  // Using a version prior to 1.1.1
  if ( version_compare( YOUR_PLUGIN_VERSION, \'1.1.1\', \'<\' ) ) {
    // Do upgrade things unique for this version.
  }

  // Using a version prior to 1.2.0
  if ( version_compare( YOUR_PLUGIN_VERSION, \'1.2.0\', \'<\' ) ) {
    // Do upgrade things unique for this version.
  }
}