在不同站点上以不同顺序对MySQL字段进行排序

Question

Let's say I have a table called "Fruits" and in that table I have a row called "Fruit" which has six entries: Apple, Banana, Kiwi, Orange, Peach, Tangerine.

I have four websites that want to sort the result of SELECT * FROM Fruits in different ways, but there is no pattern to them. They're not random , since each site will decide a different way to sort them. For example, one site might be "Kiwi, Apple, Banana, Tangerine, Orange, Peach" and the next might be, "Banana, Kiwi, Apple, Peach, Tangerine, Orange."

Can these be sorted in MySQL like this, bearing in mind that future items might be added and need to be sorted again arbitrarily at the whim of each site? Or is there a way to sort these results in PHP after they have been pulled?

Answer 1

One possible approach is setting up so-called 'sorting maps' - strings of fruit names, having the items in the exact order you want to them to be shown. Then you'll be able to use this array with FIND_IN_SET MySQL function:

$sortMap = 'Kiwi,Apple,Banana,Tangerine,Orange,Peach';

$query = >>>QUERY
   SELECT fruit_id, fruit_name
     FROM fruits
 ORDER BY FIND_IN_SET(fruit_name, '$sortMap');
QUERY;

// do something with the query

To change the ordering, just set the $sortMap on per-site basis.

Answer 2

Ok, this ended up working the best here:

    SELECT `fruit` 
    FROM (`Fruit`) 
    ORDER BY FIELD(`fruit`, 'Tangerine','Banana','Apple', 'Orange', 'Peach', 'Kiwi') ASC

As raina77ow suggested, I created a sort map to hold the values I want to inject into the query. That gets held as a config value we can switch for each site. Thanks for the direction!

Answer 3

Try this :

 SELECT * FROM Fruits ORDER BY rand()

• this will give you a random result set order !

Answer 4

You would need to assign some sort of site order identifier to each value, or at least logically group them with a fruit_type field. Otherwise you can use

SELECT ... IF(fruit = 'apple',1,0) as fruit_apple ... ORDER BY ... fruit_apple

It's an extremely inelegant solution.

Have you considered normalising the tables, moving the apples & ordering to a separate table and then joining them on request?

Answer 5

使用此ORDER BY rand（）检索值；