SQL query composition search by 4 tables - mysql

Question

I have a problem with a SQL query (i am using MySQL)
I got some tables, which have to find an output where they have to be multiplied.
First table lipid:
ID | name | mass | hg |
1 | PC 32:2 | 700 | PC |
2 | PC 32:1 | 800 | PC |
Second table FA:
ID | name | mass
1 | FA 16:1 | 300
2 | FA 16:0 | 400
3 | FA 16:2 | 200
a
Third table Cat:
ID | name | snpos | backbone | LC
1 | gpl | 2 | 25 | 1
Fourth table LC:
ID | name | mass
1 | PC | 75
I need a SQL query that can give me a result where i use something from all 4 tables.
I will need a result which can give me which composition of FA´s (table 2) that can give me the correct input lipid (table 1).
So i will input hg = PC and mass = 700. By this information it should give me which FA composition it could be.
From table 3 cat, it should use the snpos information to find out how many FA it should find in this case 2, and the backbone should be added to the result same as the mass from table 4 LC, else it will never get to the mass of input.
It would look something like:
FA 16:1 FA 16:1 (mass 600) + PC (mass 75) + backbone (25) = 700

Answer 1

This isn't intended as a definitive solution, nor even an advocation of the method; just a demonstration of principle...
DROP TABLE IF EXISTS lipid;
CREATE TABLE lipid
(ID INT NOT NULL AUTO_INCREMENT PRIMARY KEY
,name VARCHAR(12) NOT NULL UNIQUE
,mass INT NOT NULL
,hg CHAR(2) NOT NULL
);
INSERT INTO lipid VALUES
(1 ,'PC 32:2',700,'PC'),(2,'PC 32:1',800,'PC');
DROP TABLE IF EXISTS FA;
CREATE TABLE FA
(ID INT NOT NULL AUTO_INCREMENT PRIMARY KEY
,name VARCHAR(12) NOT NULL
,mass INT NOT NULL
);
INSERT INTO fa VALUES
(1 ,'FA 16:1',300),
(2 ,'FA 16:0',400),
(3 ,'FA 16:2',200);
DROP TABLE IF EXISTS Cat;
CREATE TABLE Cat
(ID INT NOT NULL AUTO_INCREMENT PRIMARY KEY
,name VARCHAR(12) NOT NULL
,snpos TINYINT NOT NULL
,backbone INT NOT NULL
,LC INT NOT NULL
);
INSERT INTO Cat VALUES
(1 ,'gpl',2,25,1);
DROP TABLE IF EXISTS LC;
CREATE TABLE LC
(ID INT NOT NULL AUTO_INCREMENT PRIMARY KEY
,name CHAR(2) NOT NULL
,mass INT NOT NULL
);
INSERT INTO LC VALUES (1,'PC',75);
SELECT l.id lipid_id
, l.name lipid_name
, l.mass lipid_mass
, l.hg
, fa.*
, c.id cat_id
, c.name cat_name
, c.snpos snpos
FROM lipid l
JOIN lc
ON lc.name = l.hg
JOIN cat c
ON c.lc = lc.id
JOIN
( SELECT 3 snpos,x.name name_x,x.mass mass_x,y.name name_y,y.mass mass_y,z.name name_z,z.mass mass_z, x.mass+y.mass+z.mass total FROM fa x JOIN fa y ON y.id < x.id JOIN fa z ON z.id < y.id
UNION
SELECT 2 ,x.name, x.mass,y.name,y.mass,NULL,0, x.mass+y.mass FROM fa x JOIN fa y ON y.id < x.id
UNION
SELECT 1,name,mass,NULL,0,NULL,0, mass FROM fa
) fa
ON fa.snpos = c.snpos
AND fa.total = 700-c.backbone-lc.mass
WHERE l.mass = 700
AND l.hg = 'PC';
+----------+------------+------------+----+-------+---------+--------+---------+--------+--------+--------+-------+--------+----------+-------+
| lipid_id | lipid_name | lipid_mass | hg | snpos | name_x | mass_x | name_y | mass_y | name_z | mass_z | total | cat_id | cat_name | snpos |
+----------+------------+------------+----+-------+---------+--------+---------+--------+--------+--------+-------+--------+----------+-------+
| 1 | PC 32:2 | 700 | PC | 2 | FA 16:2 | 200 | FA 16:0 | 400 | NULL | 0 | 600 | 1 | gpl | 2 |
+----------+------------+------------+----+-------+---------+--------+---------+--------+--------+--------+-------+--------+----------+-------+