/**
* Get the SQL syntax for a key.
*
* @param array $columns An array of SimpleXMLElement objects comprising the key.
*
* @return string
*
* @since 11.1
*/
protected function getKeySQL($columns)
{
// TODO Error checking on array and element types.
$kNonUnique = (string) $columns[0]['Non_unique'];
$kName = (string) $columns[0]['Key_name'];
$kColumn = (string) $columns[0]['Column_name'];
$prefix = '';
if ($kName == 'PRIMARY')
{
$prefix = 'PRIMARY ';
}
elseif ($kNonUnique == 0)
{
$prefix = 'UNIQUE ';
}
$nColumns = count($columns);
$kColumns = array();
if ($nColumns == 1)
{
$kColumns[] = $this->db->quoteName($kColumn);
}
else
{
foreach ($columns as $column)
{
$kColumns[] = (string) $column['Column_name'];
}
}
$sql = $prefix . 'KEY ' . ($kName != 'PRIMARY' ? $this->db->quoteName($kName) : '') . ' (' . implode(',', $kColumns) . ')';
return $sql;
}
