title: How to implement a MySQL table that the row order can be customized?
body: <p>I'd like to save some data in a MySQL table. The data have their orders which can be modified at my will. Say I have 10 rows. I want to move the 10th row to the 5th position, or insert some more rows between 2nd and 3rd position. Then, with a viewer I can get the data with the order I set. How can I implement such a table?  </p>
  
  <p>As I thought, I would save the order as float number in a new column. Each time I change the order, say, move 10th row between 5th and 6th, I would get the order number of 5th and 6th and get the average number of them, and update the order column of 10th row. Then I can get the data that ORDER BY order column. But I don't think it's a good idea. Any help about this problem?</p>