How to modiff my query to obtain the desired result? - mysql

Question

I have two tables (champ_value and champ_form), i tried two queries but i didn't obtain the result that I want,
please can you give me other solution
Thanks in advance.
+-------------+-----------+---------------------+---------------+
| champ value | | | |
| | | | |
| v_id | v_value | v_fk_order_item_id | v_fk_champ_id |
| 220 | Bernad | 20000 | 1 |
| 221 | Lagaf | 20000 | 2 |
| 500 | Vincent | 20000 | 1 |
| 501 | Pernault | 20000 | 2 |
+-------------+-----------+---------------------+---------------+
+------------+-------------+---------------+-------------+
| champ_form | | | |
| cf_id | cf_position | cf_fk_form_id | cf_champ_id |
| 330 | 10 | 1800 | 1 |
| 331 | 12 | 1800 | 2 |
| 630 | 13 | 1800 | 1 |
| 631 | 14 | 1800 | 2 |
+------------+-------------+---------------+-------------+
the desired result will be like this :
+----------------+-------+-------------+-------------+----------+
| desired result | | | | |
| | | | | |
| v_id | cf_id | cf_position | cf_champ_id | v_value |
| 220 | 330 | 10 | 1 | Bernard |
| 221 | 331 | 12 | 2 | Lagaf |
| 500 | 630 | 13 | 1 | Vincent |
| 501 | 631 | 14 | 2 | Pernault |
+----------------+-------+-------------+-------------+----------+
I tried this first query :
SELECT v.v_id, cf.cf_id, cf.cf_position, cf.cf_champ_id, v.v_value
FROM champ_form cf
JOIN champ_value v ON v.v_fk_champ_id = cf.cf_champ_id
WHERE cf.cf_fk_form_id =1800
AND v.v_fk_order_item_id =20000
GROUP BY v_id
ORDER BY cf.cf_position
and I obtain this :
+---------------+-------+-------------+-------------+----------+
| group by v_id | | | | |
| | | | | |
| v_id | cf_id | cf_position | cf_champ_id | v_value |
| 220 | 330 | 10 | 1 | Bernard |
| 221 | 330 | 10 | 1 | Vincent |
| 500 | 331 | 12 | 2 | Lagaf |
| 501 | 331 | 12 | 2 | Pernault |
+---------------+-------+-------------+-------------+----------+
and the second query :
SELECT v.v_id, cf.cf_id, cf.cf_position, cf.cf_champ_id, v.v_value
FROM champ_form cf
JOIN champ_value v ON v.v_fk_champ_id = cf.cf_champ_id
WHERE cf.cf_fk_form_id =1800
AND v.v_fk_order_item_id =20000
GROUP BY cf.cf_id
ORDER BY cf.cf_position
+----------------+-------+-------------+-------------+---------+
| group by cf_id | | | | |
| | | | | |
| v_id | cf_id | cf_position | cf_champ_id | v_value |
| 220 | 330 | 10 | 1 | Bernard |
| 221 | 331 | 12 | 2 | Lagaf |
| 220 | 630 | 13 | 1 | Bernard |
| 221 | 631 | 14 | 2 | Lagaf |
+----------------+-------+-------------+-------------+---------+
The first query gives the good values but not the correct positions
and the second gives the correct positions but not the correct values.

Answer 1

Without describing the desired behavior is difficult to understand what you want. But probably the problem is that the selected columns are not in the GROUP BY.
Try the following:
SELECT aa.v_id, cc.cf_id, cc.cf_position, cc.cf_champ_id, aa.v_value
FROM champ_value AS aa
INNER JOIN (
SELECT _aa.v_id
FROM champ_value AS _aa
INNER JOIN champ_form AS _bb
ON _aa.v_fk_champ_id = _bb.cf_champ_id
WHERE _aa.cf_fk_form_id = 1800 AND _bb.v_fk_order_item_id = 20000
GROUP BY _aa.v_id
) AS bb
ON aa.v_id = bb.v_id
INNER JOIN champ_form AS cc
ON aa.v_fk_champ_id = cc.cf_champ_id
ORDER BY aa.cf_position
More info here and here.

Answer 2

This does display according to position - still not convinced it's safe though!
/*
create table champ_value ( v_id int, v_value varchar(10), v_fk_order_item_id int, v_fk_champ_id int);
truncate table champ_value;
insert into champ_value values
(220 , 'Bernad' , 20000 , 1 ),
(221 , 'Lagaf' , 20000 , 2 ),
(500 , 'Vincent' , 20000 , 1 ),
(501 , 'Pernault' , 20000 , 2 );
create table champ_form(cf_id int,cf_position int, cf_fk_form_id int ,cf_champ_id int);
insert into champ_form values
(330 , 10 , 1800 , 1 ),
(331 , 12 , 1800 , 2 ),
(630 , 13 , 1800 , 1 ),
(631 , 14 , 1800 , 2 );
+----------------+-------+-------------+-------------+----------+
| desired result | | | | |
| | | | | |
| v_id | cf_id | cf_position | cf_champ_id | v_value |
| 220 | 330 | 10 | 1 | Bernard |
| 221 | 331 | 12 | 2 | Lagaf |
| 500 | 630 | 13 | 1 | Vincent |
| 501 | 631 | 14 | 2 | Pernault |
+----------------+-------+-------------+-------------+----------+
*/
SELECT s.v_id,t.cf_id, t.cf_position ,t.cf_champ_id ,s.v_value
FROM
(
SELECT I.v_id,v_value,v_fk_order_item_id,v_fk_champ_id,
#RN:=#RN + 1 RN
FROM (SELECT #RN:=0) RN,champ_value I
order by i.v_id asc
) S
LEFT OUTER JOIN
(SELECT cf_id,cf_position, cf_fk_form_id,cf_champ_id,
#RN1:=#RN1 + 1 RN1
FROM (SELECT #RN1:=0) RN1, champ_form E
order by e.cf_id asc
) T ON T.RN1 = S.RN
Actual Result
+------+-------+-------------+-------------+----------+
| v_id | cf_id | cf_position | cf_champ_id | v_value |
+------+-------+-------------+-------------+----------+
| 220 | 330 | 10 | 1 | Bernad |
| 221 | 331 | 12 | 2 | Lagaf |
| 500 | 630 | 13 | 1 | Vincent |
| 501 | 631 | 14 | 2 | Pernault |
+------+-------+-------------+-------------+----------+