sort result of sql query by order of field in where clause of query

问题

I want to sort the result of this query according to the contains of the query :

here it is :

SELECT a from Frais a where a.libelle = 'FRET' or a.libelle = 'Douane' or a.libelle = 'Transitaire'

I would like to have the records that have FRET first and Douane after and so on

order by libelle 

doesn't resolve the problem it sort them according to alphabetic order asc or desc

回答1:

SELECT a from Frais a where a.libelle = 'FRET' or a.libelle = 'Douane' or a.libelle = 'Transitaire'
order by case a.libelle when 'FRET' then 0 when 'Douane' then 1 when 'Transitaire' then 2 end

回答2:

One option is to use a CASE statement:

SELECT * 
FROM Frais a 
WHERE a.libelle = 'FRET' 
   OR a.libelle = 'Douane' 
   OR a.libelle = 'Transitaire'
ORDER BY 
   CASE 
     WHEN a.libelle = 'FRET' THEN 1
     WHEN a.libelle = 'Douane' THEN 2
     WHEN a.libelle = 'Transitaire' THEN 3
   END

回答3:

You can also do this by putting the values in a "temporary" table that has an explicit ordering:

select f.*
from frais f join
     (select 'FRET' as val, 1 as ord union all
      select 'Douane', 2 union all
      select 'Transitaire', 3
     ) vals
     on f.libelle = vals.val
order by vals.ord

来源：https://stackoverflow.com/questions/16425430/sort-result-of-sql-query-by-order-of-field-in-where-clause-of-query