mysql group concat into multiple fields - mysql

Question

I have a recipe table, called recipes. There is the IDRecipe field and other parameters of the recipe except the categories. Categories are multi dimensional, so I have another table that connects one to many with one recipe. It is called category table (table 1 below). As you will see below, one recipe can have multiple categories in multiple dimensions. So I have another table (table 2) that describes the categories and dimensions, also below:
-- Table 1
CREATE TABLE `recepti_kategorije` (
`IDRecipe` int(11) NOT NULL,
`IDdimenzija` int(11) NOT NULL,
`IDKategorija` int(11) NOT NULL,
KEY `Iskanje` (`IDdimenzija`,`IDKategorija`,`IDRecipe`) USING BTREE,
KEY `izvlecek_recept` (`IDdimenzija`,`IDRecipe`),
KEY `IDRecipe` (`IDRecept`,`IDdimenzija`,`IDKategorija`) USING BTREE,
KEY `kategorija` (`IDKategorija`,`IDdimenzija`,`IDRecipe`) USING BTREE
) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_slovenian_ci;
INSERT INTO `recepti_kategorije` VALUES
(1,1,1),
(1,1,2),
(1,2,3),
(1,3,2);
-- Table 2
CREATE TABLE `recipes_dimensions` (
`IDDimenzija` int(11) NOT NULL,
`IDKategorija` int(11) NOT NULL,
`Ime` char(50) COLLATE utf8_slovenian_ci NOT NULL,
KEY `IDDmenzija` (`IDDimenzija`,`IDKategorija`) USING BTREE,
KEY `IDKategorija` (`IDKategorija`,`IDDimenzija`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_slovenian_ci;
INSERT INTO `recipes_dimensions` VALUES
(1,1,'cheese'),
(1,2,'eggs'),
(1,3,'meat'),
(1,4,'vegetables'),
(2,1,'main dish'),
(2,2,'sweet'),
(2,3,'soup'),
(3,1,'summer'),
(3,2,'winter');
-- Table 3
CREATE TABLE `recepti_dimenzije_glavne` (
`IDDimenzija` int(11) NOT NULL,
`DimenzijaIme` char(50) COLLATE utf8_slovenian_ci DEFAULT NULL,
PRIMARY KEY (`IDDimenzija`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_slovenian_ci;
INSERT INTO `recepti_dimenzije_glavne` VALUES
(1,'ingredient'),
(2,'type'),
(3,'season');
Table 2 is the key table to find out the legend of each dimensions and each category.
So from this example we see that my recipe with ID1 has the tag: cheese and eggs from dimension 1 and is soup for winter season.
Now on my recipes page I need to get all this out to print the names of each dimension together with all the category names.
Ok, so there is another table, table 3, to get the names of the dimensions out:
Now what I need is a query that would get me at the same time for recipe ID=1 all the dimensions group concatenated with names, like:
ingredient: cheese, eggs | type: soup | season: winter
I tried doing a query for each of them in SELECT statement and it works, but I need 8 select queries (in total I have 8 dimensions, for the example I only wrote 3), my select query is:
SELECT
r.ID
(
SELECT
group_concat(ime SEPARATOR ', ')
FROM
recepti_kategorije rkat
JOIN recepti_dimenzije rd ON rd.IDKategorija = rkat.IDKategorija
AND rd.IDDimenzija = rkat.IDdimenzija
WHERE
rkat.IDRecipe = r.ID
AND rkat.IDDimenzija = 1
ORDER BY
ime ASC
) AS ingredient,
(
SELECT
group_concat(ime SEPARATOR ', ')
FROM
recepti_kategorije rkat
JOIN recepti_dimenzije rd ON rd.IDKategorija = rkat.IDKategorija
AND rd.IDDimenzija = rkat.IDdimenzija
WHERE
rkat.IDRecipe = r.ID
AND rkat.IDDimenzija = 2
ORDER BY
ime ASC
) AS type,
(
SELECT
group_concat(ime SEPARATOR ', ')
FROM
recepti_kategorije rkat
JOIN recepti_dimenzije rd ON rd.IDKategorija = rkat.IDKategorija
AND rd.IDDimenzija = rkat.IDdimenzija
WHERE
rkat.IDRecipe = r.ID
AND rkat.IDDimenzija = 3
ORDER BY
ime ASC
) AS season
FROM
recipes r
WHERE
r.ID = 1
That works, but it is somehow slow because the explain says it is searching like 6-8 rows each time and it is a long query and I don't get the names of the dimensions out because I need another join.
What would be optimal way to get all the dimensions separated into fields and concated with category names? I need to have this optimised as this is for one recipe presentation that happens each second, I can not fool around here. And whta indexes do I need so that this would be fast.

Answer 1

Something like below, not sure I typed the table/column names right or not, but should be easy to debug:
SELECT c.ID,GROUP_CONCAT(CONCAT(d.DimenzijaIme,': ',c.imes) SEPARATOR ' | ')
FROM (
SELECT
r.ID,rkat.IDDimenzija,
group_concat(rd.ime SEPARATOR ', ' ORDER BY rd.ime) AS imes
FROM recepti_kategorije rkat
JOIN recepti_dimenzije rd
ON rd.IDKategorija = rkat.IDKategorija
AND rd.IDDimenzija = rkat.IDdimenzija
INNER JOIN recipes r
ON r.ID=rkat.IDRecipe
GROUP BY r.ID,rkat.IDDimenzija) c
INNER JOIN recepti_dimenzije_glavne d
ON d.IDDimenzija=c.IDDimenzija
GROUP BY c.ID