<?php
defined('IN_YZMPHP') or exit('Access Denied'); 

class sql{
	
	public static $tablename;

	
	public static function set_tablename($tablename){
		self::$tablename = C('db_prefix').$tablename;
	}

	
	public static function sql_create($tablename){
		self::set_tablename($tablename);
		self::sql_delete($tablename);
		$sql = "CREATE TABLE `".self::$tablename."` (
			  `id` int(10) unsigned NOT NULL auto_increment,
			  `userid` mediumint(8) unsigned NOT NULL DEFAULT '0',
			  `username` varchar(30) NOT NULL DEFAULT '',
			  `ip` varchar(15) NOT NULL DEFAULT '',
			  `inputtime` int(10) unsigned NOT NULL DEFAULT '0',
			  PRIMARY KEY (`id`)
			) ENGINE=MyISAM DEFAULT CHARSET=utf8;";
        self::sql_exec($sql);			
	}
	
	
	public static function sql_delete($tablename){
		self::set_tablename($tablename);
		$sql = "DROP TABLE IF EXISTS `".self::$tablename."`";
		self::sql_exec($sql);			
	}


	public static function sql_add_field($tablename, $field, $defaultvalue='', $maxlength=250){
		self::set_tablename($tablename);
		$sql = "ALTER TABLE `".self::$tablename."` ADD COLUMN `$field` varchar($maxlength) NOT NULL DEFAULT '$defaultvalue'";
		self::sql_exec($sql);			
	}


	public static function sql_add_field_mediumtext($tablename, $field){
		self::set_tablename($tablename);
		$sql = "ALTER TABLE `".self::$tablename."` ADD COLUMN `$field` mediumtext NOT NULL";
		self::sql_exec($sql);			
	}
	
	
	public static function sql_add_field_text($tablename, $field){
		self::set_tablename($tablename);
		$sql = "ALTER TABLE `".self::$tablename."` ADD COLUMN `$field` text NOT NULL";
		self::sql_exec($sql);			
	}
	
	
	public static function sql_add_field_int($tablename, $field, $defaultvalue=0){
		self::set_tablename($tablename);
		$sql = "ALTER TABLE `".self::$tablename."` ADD COLUMN `$field` int(10) UNSIGNED NOT NULL DEFAULT $defaultvalue";
		self::sql_exec($sql);			
	}
	

	public static function sql_del_field($tablename, $field){
		self::set_tablename($tablename);
		$sql = "ALTER TABLE `".self::$tablename."` DROP COLUMN `$field`";
		self::sql_exec($sql);			
	}

	
    public static function sql_exec($sql){
		global $model;
		$model = isset($model) ? $model : D('model');
		$model->query($sql);
	}	
}



