public function __construct($table, $columnNames, $indexName)
{
$columns = array();
$columnNamesOnly = array();
foreach ($columnNames as $columnName) {
$columnName = str_replace(' ', '', $columnName);
// eg "column_name (10)" => "column_name(10)"
preg_match('/^([\\w]+)(\\(?\\d*\\)?)$/', $columnName, $matches);
// match "column_name" and "column_name(10)"
$nameOnly = $matches[1];
// eg "column_name"
$columnNamesOnly[] = $nameOnly;
$column = "`{$nameOnly}`";
if (!empty($matches[2])) {
$column .= ' ' . $matches[2];
// eg "(10)"
}
$columns[] = $column;
}
if (empty($indexName)) {
$indexName = $this->indexNamePrefix . '_' . implode('_', $columnNamesOnly);
}
$sql = sprintf("ALTER TABLE `%s` ADD %s %s (%s)", $table, $this->indexType, $indexName, implode(', ', $columns));
parent::__construct($sql, array(static::ERROR_CODE_DUPLICATE_KEY, static::ERROR_CODE_KEY_COLUMN_NOT_EXISTS));
}