mysql中文排序问题

mysql中文排序，用到的是：

SELECT 
  id id,
  billId billId,
  namespec nameSpec,
  unit unit,
  amount amount,
  price price,
  remark remark,
  alias alias,
  materialType materialType 
FROM
  project_materials 
WHERE billId = 'TLD20151028162729584' 
ORDER BY CONVERT(nameSpec USING gbk) 
LIMIT 0, 20 

ORDER BY CONVERT(nameSpec USING gbk) 是重点。

还有一句强制转换：如下：

SELECT 
  id id,
  billId billId,
  namespec nameSpec,
  unit unit,
  amount amount,
  price price,
  remark remark,
  alias alias,
  materialType materialType 
FROM
  project_materials 
WHERE billId = 'TLD20151028162729584' 
ORDER BY CONVERT(nameSpec USING gbk) COLLATE gbk_chinese_ci 
LIMIT 0, 20