MySQL - return reference via multiple table joins - mysql

Question

TABLE 'styles'
id|style_code
1|6110
2|6120
3|6250
TABLE 'colour'
id|colour_code
1|1001
2|1012
3|1033
4|1050
TABLE 'styleColour'
id|style_id|colour_id|cancelled
1 | 1 | 1 |
2 | 1 | 2 | y
3 | 2 | 1 |
4 | 2 | 3 |
5 | 2 | 4 |
6 | 3 | 1 |
7 | 3 | 2 |
8 | 3 | 3 | y
9 | 3 | 4 | y
TABLE 'orders'
id|style_code|colour_code
1 | 6110 | 1001
2 | 6110 | 1012
3 | 6130 | 1001
4 | 6130 | 1033
5 | 6130 | 1050
6 | 6250 | 1033
7 | 6250 | 1050
Output wanted (based on 'order' table):
style_code|colour_code|cancelled
6110 | 1001 |
6110 | 1012 | y
6130 | 1001 |
6130 | 1033 |
6130 | 1050 |
6250 | 1033 | y
6250 | 1050 | y
What joins are needed to reference the 'cancelled' column to the appropriate style_code and colour_code combination on the 'order' table ouput?
Please bear in mind that although it may seem odd that the 'style_code' and 'colour_code' data as shown rather than being represented by style_id and colour_id, this is required for importing reasons.
Thanks and kind regards,
Derek.

Answer 1

Updated answer as per comments below -
SELECT orders.style_code,orders.colour_code,styleColour.cancelled
FROM orders
LEFT JOIN colours ON orders.colour_code=colours.colour_code
LEFT JOIN styles ON orders.style_code=styles.style_code
LEFT JOIN styleColour ON styleColour.style_id=styles.id
AND styleColour.colour_id=colours.id;
However if you make the JOINs on colours/styles being on the id column instead of the code column (I assume id is the primary key), it might be faster (as primary keys are indexed).
This is my attempt at that. I haven't tested it, but give it a try:
SELECT orders.style_code,orders.colour_code,styleColour.cancelled
FROM styleColour
RIGHT JOIN colours ON orders.colour_id=colours.id
RIGHT JOIN styles ON orders.style_id=styles.id
RIGHT JOIN orders ON orders.style_code=styles.style_code
AND orders.colour_code=colours.colour_code;
The reason it's all RIGHT JOINs is to do all the joining based on the rows in orders as opposed to styleColour.