<?
function db_update_218_pre() 
{
}

function db_update_218_post()
{
	$tables=array(
		'questions',
		'fairs_stats'
	);

	// add the conferences_id field
	foreach($tables as $tableName){
		$query = "ALTER TABLE `$tableName` ADD `conferences_id` INT NOT NULL";
		mysql_query($query);
		echo $query . ";\n";
	}

	// get the year => conference_id links
	$q1 = mysql_query("SELECT year, id FROM conferences WHERE year > 0");

	// add the conferences_id field to each table
	while($r = mysql_fetch_assoc($q1)){
		foreach($tables as $tableName){
			$query = "UPDATE `$tableName` SET `conferences_id` = {$r['id']} WHERE `year` = {$r['year']}";
			mysql_query($query);
			echo $query . ";\n";
		}
	}
}
?>