core/DB.php
public static function addField(string $tbname, string $field, array $options = [])
    {
        return self::engine()->addField($tbname, $field, $options);
    }
public static function addField(string $tbname, string $field, array $options = [])
    {
        return self::engine()->addField($tbname, $field, $options);
    }
添加字段
@param string $tbname
@param string $field
@param array $options
@return int
@throws MysqlException