/** * Returns a Field object. If the column is NOT in the table, a * Error is thrown by the Field constructor * @param string $column_name Name of the column in this table * @param string $alias Query alias used when referencing this field * @return Field */ public function getField($column_name, $alias = null) { if (!$this->db->allowed($column_name)) { throw new \Exception(t('Improper column name "%s"', $column_name)); } $field = new Field($this, $column_name, $alias); if (!($field->allowSplat() && $column_name == '*') && (DATABASE_CHECK_COLUMNS && !$this->columnExists($column_name))) { throw new \Exception(t('Column does not exist in %s "%s"', get_class($this), $this->getFullName())); } return $field; }