相同的SQL查询不同的结果？

Question

I have this Sql query

SELECT tt.ID_Partenaire, tt.Nom_Societe,tt.Image_Societe, tt.id_activite 
                FROM affiliate AS a 
                RIGHT JOIN 
                  (SELECT partenaires.ID_Partenaire, 
                  partenaires.Nom_Societe, partenaires.Image_Societe, partenaires.id_activite,
                        IFNULL(SUM(c.montant_real),0) AS mt1 
                    FROM partenaires
                        LEFT JOIN commande AS c 
                    ON partenaires.ID_Partenaire=c.id_partenaire 
                    GROUP BY partenaires.ID_Partenaire 
                  )AS tt 
            ON a.id_partenaire= tt.ID_Partenaire 
            GROUP BY tt.ID_Partenaire 
            ORDER BY (IFNULL(SUM(a.montat),0) + mt1) DESC 
            LIMIT 20

I have two server :

1. Version du serveur : 5.7.11-log - MySQL Community Server (GPL) -locally-
2. Server version: 10.1.25-MariaDB-1~jessie - mariadb.org binary distribution - host -

When i execute it on these servers, each one of them give me a different result.

I think the problem is in the ORDER BY

As a solution i made :

SELECT ID_Partenaire, Nom_Societe, Image_Societe, id_activite 
      FROM (SELECT tt.ID_Partenaire, tt.Nom_Societe,tt.Image_Societe, 
             tt.id_activite, 
             (IFNULL(SUM(a.montat),0) + mt1) as mm
                FROM affiliate AS a 
                RIGHT JOIN 
                  (SELECT partenaires.ID_Partenaire, 
                       partenaires.Nom_Societe, partenaires.Image_Societe, 
                       partenaires.id_activite,
                        IFNULL(SUM(c.montant_real),0) AS mt1 
                    FROM partenaires
                        LEFT JOIN commande AS c 
                    ON partenaires.ID_Partenaire=c.id_partenaire 
                    GROUP BY partenaires.ID_Partenaire 
                  )AS tt 
            ON a.id_partenaire= tt.ID_Partenaire 
            GROUP BY tt.ID_Partenaire 
            ORDER BY mm DESC 
            LIMIT 20) AS k

I am really confused because MySql does not give me any error but gives different result, i have other queries and i am afraid that he is doing the same for them !

Answer 1

You can find the difference using explain report . Just run explain extended SELECT ID_Partenaire, Nom_Societe... .

Answer 2

Add the limit after the order by block. 'limit' and 'order by' is in same level 'limit' done before the 'order by' happen, so give different result

try something like this

SELECT ID_Partenaire,
  Nom_Societe,
  Image_Societe,
  id_activite
FROM
  (SELECT tt.ID_Partenaire,
    tt.Nom_Societe,
    tt.Image_Societe,
    tt.id_activite,
    (IFNULL(SUM(a.montat),0) + mt1) AS mm
  FROM affiliate                    AS a
  RIGHT JOIN
    (SELECT partenaires.ID_Partenaire,
      partenaires.Nom_Societe,
      partenaires.Image_Societe,
      partenaires.id_activite,
      IFNULL(SUM(c.montant_real),0) AS mt1
    FROM partenaires
    LEFT JOIN commande AS c
    ON partenaires.ID_Partenaire=c.id_partenaire
    GROUP BY partenaires.ID_Partenaire
    )AS tt ON a.id_partenaire= tt.ID_Partenaire
  GROUP BY tt.ID_Partenaire
  ORDER BY mm DESC
  ) AS k LIMIT 20