The column creation appears only in verison 1.0.16:
/**
* 1.0.16 Upgrade Code
*/
class ips_plugins_setup_upg_10019
{
/**
* ...
*
* @return array If returns TRUE, upgrader will proceed to next step. If it returns any other value, it will set this as the value of the 'extra' GET parameter and rerun this step (useful for loops)
*/
public function step1()
{
if( !\IPS\Db::i()->checkForColumn( 'core_members', 'banned_from_clubs' ) )
{
\IPS\Db::i()->addColumn( 'core_members', array(
'name' => 'banned_from_clubs',
'type' => 'TINYINT',
'length' => 1,
'allow_null' => false,
'default' => '0',
'comment' => "Determines if the member is banned from the WHOLE Clubs module.",
'unsigned' => true,
) );
}
return TRUE;
}
// You can create as many additional methods (step2, step3, etc.) as is necessary.
// Each step will be executed in a new HTTP request
}
So there's absolutely no way to show duplicate column, unless something happened when you tried to update and the column was created and then you tried again.
Anyway, here goes the live update from 1.0.15.1 to 1.0.16 (column is created here) to 1.0.16.1:
No problem here.