Questions about a very complex MySQL query arrangement scenario

A product contains a

Item number warehouse size color number and other data
MySQL is also stored in such a field, but there is the same article number, not the same warehouse, different size situation

Now I need to select out the data format requirement is

Item No. 001 Size Color Quantity
———— Catalog No. 001 Warehouse 002 Size 1 Quantity size 2 quantity size 3 quantity
Item 2--Catalog No. 002 Size Color Quantity
———— Catalog No. 002 Warehouse 002 Size 1 Quantity size 2 quantity size 3 quantity
———— Catalog No. 002 Warehouse 003 Size 1 Quantity size 2 quantity size 3 quantity
Item 3--Catalog No. 003 Size Color
———— Catalog No. 003 Warehouse 003 Size 1 Quantity size 2 quantity size 3 quantity
....

That is, the same article number of the goods merged and then divided into different warehouses and different sizes
How would I write the SELECT statement?
I think it is to write multi-layered, the best way to be efficient?

Reply content:

A product contains a

Item number warehouse size color number and other data
MySQL is also stored in such a field, but there is the same article number, not the same warehouse, different size situation

Now I need to select out the data format requirement is

Item No. 001 Size Color Quantity
———— Catalog No. 001 Warehouse 002 Size 1 Quantity size 2 quantity size 3 quantity
Item 2--Catalog No. 002 Size Color Quantity
———— Catalog No. 002 Warehouse 002 Size 1 Quantity size 2 quantity size 3 quantity
———— Catalog No. 002 Warehouse 003 Size 1 Quantity size 2 quantity size 3 quantity
Item 3--Catalog No. 003 Size Color
———— Catalog No. 003 Warehouse 003 Size 1 Quantity size 2 quantity size 3 quantity
....

That is, the same article number of the goods merged and then divided into different warehouses and different sizes
How would I write the SELECT statement?
I think it is to write multi-layered, the best way to be efficient?

What you need to consider is the SKU

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