SQL语句如何优化，这样的搜索请求, 给个思路。指点一二 400 请求报错 

/*获取筛选属性*/
$attr_para = $_GET['para']; 		//形状
$attr_cut = $_GET['cut']; 			//切工
$attr_color = $_GET['color']; 		//颜色
$attr_symmetry = $_GET['symmetry'];	//对称
$attr_clarity = $_GET['clarity'];	//净度
$attr_polish = $_GET['polish'];		//抛光
$attr_cert = $_GET['cert'];		    //证书
$attr_location = $_GET['location'];		//所在地

 /* 属性筛选 */
	$attr_r = '';	//页面输出筛选条件
	if($attr_cut){
		$attr_str='';
		$cut_where='';
		foreach($attr_cut as $key=>$value){
			if($key==0){$attr_str.='\''.$value.'\'';}
			else{$attr_str.=',\''.$value.'\'';}	
			$temp = 'cut_'.$value;
			$$temp = 1;
			$smarty->assign("$temp",      $$temp);  // 输出已筛选条件
		}
		$cut_where = ' AND attr_value in('.$attr_str.')';
		$attr_r .= '切工：'.$attr_str.' ';
	}


	$sql = 'SELECT g.goods_id,g.goods_name,g.goods_sn,g.market_price,g.shop_price,g.promote_price,g.promote_start_date,g.promote_end_date';
	
	$sql.= ',cut';
	$sql.= ',color';
	$sql.= ',symmetry';
	$sql.= ',clarity';
	$sql.= ',polish';
	$sql.= ',cert';
	$sql.= ',carat';
	$sql.= ',location';
	$sql.= ',certificate';
	
	$sql_f.= ' FROM ' . $GLOBALS['ecs']->table('goods') .' AS g ';
	
	$sql_f.= ',(SELECT goods_id, attr_value AS cut FROM ' . $GLOBALS['ecs']->table('goods_attr') .' WHERE attr_id=2'.$cut_where.') AS cut';
	$sql_f.= ',(SELECT goods_id, attr_value AS color FROM ' . $GLOBALS['ecs']->table('goods_attr') .' WHERE attr_id=3'.$color_where.') AS color';
	$sql_f.= ',(SELECT goods_id, attr_value AS symmetry FROM ' . $GLOBALS['ecs']->table('goods_attr') .' WHERE attr_id=6'.$symmetry_where.') AS symmetry';
	$sql_f.= ',(SELECT goods_id, attr_value AS clarity FROM ' . $GLOBALS['ecs']->table('goods_attr') .' WHERE attr_id=4'.$clarity_where.') AS clarity';
	$sql_f.= ',(SELECT goods_id, attr_value AS polish FROM ' . $GLOBALS['ecs']->table('goods_attr') .' WHERE attr_id=5'.$polish_where.') AS polish';
	$sql_f.= ',(SELECT goods_id, attr_value AS cert FROM ' . $GLOBALS['ecs']->table('goods_attr') .' WHERE attr_id=8'.$cert_where.') AS cert';
	$sql_f.= ',(SELECT goods_id, attr_value AS carat FROM ' . $GLOBALS['ecs']->table('goods_attr') .' WHERE attr_id=1'.$carat_where.') AS carat';
	$sql_f.= ',(SELECT goods_id, attr_value AS location FROM ' . $GLOBALS['ecs']->table('goods_attr') .' WHERE attr_id=62) AS location';
	$sql_f.= ',(SELECT goods_id, attr_value AS certificate FROM ' . $GLOBALS['ecs']->table('goods_attr') .' WHERE attr_id=8) AS certificate';
	
	$sql_f.= ' WHERE g.goods_id = cut.goods_id';	
	$sql_f.= ' AND g.goods_id = color.goods_id';	
	$sql_f.= ' AND g.goods_id = symmetry.goods_id';	
	$sql_f.= ' AND g.goods_id = clarity.goods_id';	
	$sql_f.= ' AND g.goods_id = polish.goods_id';
	$sql_f.= ' AND g.goods_id = cert.goods_id';
	$sql_f.= ' AND g.goods_id = carat.goods_id';	
	$sql_f.= ' AND g.goods_id = location.goods_id';	
	$sql_f.= ' AND g.goods_id = certificate.goods_id';