Mysql - Order rows that have same columns content - mysql

Question

have a Mysql table like that
id primary key ( idstudy, idarea and idcategory are foreign keys )
**** Table : Operations
id idstudy idarea idcategory content lang
1 22 11 3 content1EN EN
2 22 11 3 content1FR FR
3 22 11 3 Content2FR FR
4 22 11 3 Content2EN EN
5 35 10 5 Content5EN EN
6 35 10 5 Content5FR FR
7 35 23 12 Content5EN EN
8 35 23 12 Content5FR FR
My goal : to assemble language to same row ( FR and EN) to get one row with one column in plus ( ContentEN for example) and remove lang column.
but my problème my table is not in order, and i cant reconnize by id, all i know are idstudy idarea and idcategory but those both are not unique , and sometimes i have 3 rows that are same except (id and content)
I have solution but i dont know how to write it in mysql : is to find all records with ( same idstudy same idarea same idcategory ) in one language then order them by adding column with ( 1 for first result, 2 for the second ...)
**** Table : Operations after order of groups ( idstudy, idarea, idcategory) in each language with new column ( order)
id idstudy idarea idcategory content lang order
1 22 11 3 content1EN EN 1
2 22 11 3 content1FR FR 1
3 22 11 3 Content2FR FR 2
4 22 11 3 Content2EN EN 1
5 35 10 5 Content5EN EN 1
6 35 10 5 Content5FR FR 1
7 35 23 12 Content5EN EN 1
8 35 23 12 Content5FR FR 1
I just need this result , after to assemble iwill do it using nodejs
note: sorry if my explanation is not so good.

Answer 1

Try this:
SELECT id, idstudy, idarea, idcategory, content, lang, dense_rank as 'order'
FROM (
SELECT
#dense:=IF(#prev_col1=t.idstudy AND #prev_col2=t.idarea AND #prev_col3=t.idcategory AND #prev_col4=t.lang, IF(#prev_col5=t.content, #dense, #dense+1), 1) AS dense_rank,
t.*,
#prev_col1:=t.idstudy, #prev_col2:=t.idarea, #prev_col3:=t.idcategory, #prev_col4:=t.lang, #prev_col5:=t.content
FROM (SELECT * FROM t1 ORDER BY idstudy, idarea, idcategory, lang, content ) t,
(SELECT #dense:=1, #prev_col1:=NULL, #prev_col2:=NULL, #prev_col3:=NULL, #prev_col4:=NULL, #prev_col5:=NULL) var
) F
ORDER BY idstudy, idarea, idcategory, lang, content;
In MySql you can mimic ms-sql analytics functions in this way Analytical Function in MySQL - ROW_NUMBER, RANK, DENSE_RANK
In SQL-Sever you could use DENSE_RANK()
SELECT *, DENSE_RANK() OVER (PARTITION BY idstudy, idarea, idcategory, lang ORDER BY content) [order]
FROM tableName

Answer 2

Fianllay i found another solution , i made two tables with same structure ( french and english), regenerate id of eeach table ( to be 1.2.3.for each).
As i have 500 rows in each table i checked each row if its Ok ( each id must concern same content in two languages )
Special thanks to #MtwStark for his time :) i appreciate your help
Sometimes when we try to explain our problem we find the solution :)