You could have a design like:
+---------------+ +-------------------+
| PRODUCTS |-----< PRODUCT_VARIANTS |
+---------------+ +-------------------+
| #product_id | | #product_id |
| product_name | | #variant_id |
+---------------+ | sku_id |
| +-------------------+
| |
+--------^--------+ +--------^--------+
| PRODUCT_OPTIONS |-----< VARIANT_VALUES |
+-----------------+ +-----------------+
| #product_id | | #product_id |
| #option_id | | #variant_id |
+--------v--------+ | #option_id |
| | value_id |
+-----------------+ +--------v--------+
| OPTIONS | |
+-----------------+ |
| #option_id | |
| option_name | |
+-----------------+ |
| |
+-------^-------+ |
| OPTION_VALUES |---------------+
+---------------+
| #option_id |
| #value_id |
| value_name |
+---------------+
With the Primary, Unique and Foreign Keys:
- PRODUCTS
- PK: product_id
- UK: product_name
- OPTIONS
- PK: option_id
- UK: option_name
- OPTION_VALUES
- PK: option_id, value_id
- UK: option_id, value_name
- FK: option_id REFERENCES OPTIONS (option_id)
- PRODUCT_OPTIONS
- PK: product_id, option_id
- FK: product_id REFERENCES PRODUCTS (product_id)
- FK: option_id REFERENCES OPTIONS (option_id)
- PRODUCT_VARIANTS
- PK: product_id, variant_id
- UK: sku_id
- FK: product_id REFERENCES PRODUCTS (product_id)
- VARIANT_VALUES
- PK: product_id, variant_id, option_id
- FK: product_id, variant_id REFERENCES PRODUCT_VARIANTS (product_id, variant_id)
- FK: product_id, option_id REFERENCES PRODUCT_OPTIONS (product_id, option_id)
- FK: option_id, value_id REFERENCES OPTION_VALUES (option_id, value_Id)
You have:
- PRODUCTS e.g. Shirt, Jumper, Trousers
- OPTIONS e.g. Size, Colour, Length
- OPTION_VALUES e.g Size – Small, Medium, Large; Colour – Red, White, Blue
- PRODUCT_OPTIONS e.g. Shirt – Size, Colour; Trousers – Length, Colour
You then need to create a n-dimensional array, with the number of dimensions equalling the number of options for the product. Each element in the array corresponds to a product variant. There will always be at least one product variant for each product; as there is always the pseudo option of the product “as-is”
- PRODUCT_VARIANTS e.g Shirt 1, Shirt 2
- VARIANT_VALUES e.g Shirt 1: Small Red; Shirt 2: Small White
You may wish to have validation to ensure a SKU is not assigned unless values have been specified for all options associated with a product.
Based on the spreadsheet of how you see your data you could enter data in your tables as follows:
PRODUCTS
========
id name
--- --------
1 Widget 1
2 Widget 2
3 Widget 3
PRODUCT_VARIANTS
================
id product_id name
--- ---------- ------
1 1 Size (Widget 1)
2 1 Color (Widget 1)
3 2 Size (Widget 2)
4 3 Class (Widget 3)
5 3 Size (Widget 3)
PRODUCT_VARIANT_OPTIONS
=======================
id product_variant_id name
--- ------------------ -------------
1 1 Small (Widget 1; Size)
2 1 Large (Widget 1; Size)
3 2 White (Widget 1; Color)
4 2 Black (Widget 1; Color)
5 3 Small (Widget 2; Size)
6 3 Medium (Widget 2; Size)
7 4 Amateur (Widget 3; Class)
8 4 Professional (Widget 3; Class)
9 5 Medium (Widget 3; Size)
10 5 Large (Widget 3; Size)
SKUS
====
id product_id sku price
--- ---------- ------ -----
1 1 W1SSCW 10 (Widget 1)
2 1 W1SSCB 10 (Widget 1)
3 1 W1SLCW 12 (Widget 1)
4 1 W1SLCB 15 (Widget 1)
5 2 W2SS 100 (Widget 2)
6 2 W2SM 100 (Widget 2)
7 3 W3CASM 50 (Widget 3)
8 3 W3CASL 50 (Widget 3)
9 3 W3CPSM 150 (Widget 3)
10 3 W3CPSL 160 (Widget 3)
PRODUCT_VARIANT_OPTION_COMBINATIONS
===================================
product_variant_option_id sku_id
------------------------- ------
1 1 (W1SSCW; Size; Small)
3 1 (W1SSCW; Color; White)
1 2 (W1SSCB; Size; Small)
4 2 (W1SSCB; Color; Black)
2 3 (W1SLCW; Size; Large)
3 3 (W1SLCW; Color; White)
2 4 (W1SLCB; Size; Large)
4 4 (W1SLCB; Color; Black)
5 5 (W2SS; Size; Small)
6 6 (W2SM; Size; Medium)
7 7 (W3CASM; Class; Amateur)
9 7 (W3CASM; Size; Medium)
7 8 (W3CASL; Class; Amateur)
10 8 (W3CASL; Size; Large)
8 9 (W3CPSM; Class; Professional)
9 9 (W3CPSM; Size; Medium)
8 10 (W3CPSL; Class; Professional)
10 10 (W3CPSL; Size; Large)
There seems to be nothing in your design from stopping the addition of the entry of the record (product_variant_option_id: 2; sku_id 1) so that SKU W1SSCW has now both the options of Small and Large. There is nothing to stop the entry of the record (product_variant_option_id: 7; sku_id: 1) so that SKU W1SSCW also has the option Amateur.
Based on the spreadsheet of how you see your data you could enter data in my tables as follows:
PRODUCTS
========
product_id product_name
---------- ------------
1 Widget 1
2 Widget 2
3 Widget 3
OPTIONS
=======
option_id option_name
--------- -----------
1 Size SL
2 Color
3 Size SM
4 Class
5 Size ML
OPTION_VALUES
=============
option_id value_id value_name
--------- -------- ------------
1 1 Small (Size SL)
1 2 Large (Size SL)
2 1 White (Color)
2 2 Black (Color)
3 1 Small (Size SM)
3 2 Medium (Size SM)
4 1 Amateur (Class)
4 2 Professional (Class)
5 1 Medium (Size ML)
5 2 Large (Size ML)
PRODUCT_OPTIONS
===============
product_id option_id
---------- ---------
1 1 (Widget 1; Size SL)
1 2 (Widget 1; Color)
2 3 (Widget 2; Size SM)
3 4 (Widget 3; Class)
3 5 (Widget 4; Size ML)
PRODUCT_VARIANTS
================
product_id variant_id sku_id
---------- ---------- ------
1 1 W1SSCW (Widget 1)
1 2 W1SSCB (Widget 1)
1 3 W1SLCW (Widget 1)
1 4 W1SLCB (Widget 1)
2 1 W2SS (Widget 2)
2 2 W2SM (Widget 2)
3 1 W3CASM (Widget 3)
3 2 W3CASL (Widget 3)
3 3 W3CPSM (Widget 3)
3 4 W3CPSL (Widget 3)
VARIANT_VALUES
==============
product_id variant_id option_id value_id
---------- ---------- --------- --------
1 1 1 1 (W1SSCW; Size SL; Small)
1 1 2 1 (W1SSCW; Color; White)
1 2 1 1 (W1SSCB; Size SL; Small)
1 2 2 2 (W1SSCB; Color; Black)
1 3 1 2 (W1SLCW; Size SL; Large)
1 3 2 1 (W1SLCW; Color; White)
1 4 1 2 (W1SLCB; Size SL; Large)
1 4 2 2 (W1SLCB; Color; Black)
2 1 3 1 (W2SS; Size SM; Small)
2 2 3 2 (W2SM; Size SM; Medium)
3 1 4 1 (W3CASM; Class; Amateur)
3 1 5 1 (W3CASM; Size ML; Medium)
3 2 4 1 (W3CASL; Class; Amateur)
3 2 5 2 (W3CASL; Size ML; Large)
3 3 4 2 (W3CPSM; Class; Professional)
3 3 5 1 (W3CPSM; Size ML; Medium)
3 4 4 2 (W3CPSL; Class; Professional)
3 4 5 2 (W3CPSL; Size ML; Large)
In my design you could not enter the additional VARIANT_VALUES record (product_id: 1; variant_id: 1; option_id: 1; value_id: 2) – so that SKU W1SSCW has now both the options of Small and Large – due to the primary key on VARIANT_VALUES and the existing VARIANT_VALUES record (product_id: 1; variant_id: 1; option_id: 1; value_id: 1). In my design you could not enter the VARIANT_VALUES record (product_id: 1; variant_id: 1; option_id: 4; value_id: 1) – so that SKU W1SSCW also has the option Amateur – due to the foreign key referencing PRODUCT_OPTIONS and the lack of a record in this table of (product_id: 1; option_id: 4) indicating that Class is a valid option for product Widget 1.
EDIT: Design with no PRODUCT_OPTIONS table
You could have a design like:
+---------------+ +---------------+
| PRODUCTS |-----< PRODUCT_SKUS |
+---------------+ +---------------+
| #product_id | | #product_id |
| product_name | | #sku_id |
+---------------+ | sku |
| | price |
| +---------------+
| |
+-------^-------+ +------^------+
| OPTIONS |------< SKU_VALUES |
+---------------+ +-------------+
| #product_id | | #product_id |
| #option_id | | #sku_id |
| option_name | | #option_id |
+---------------+ | value_id |
| +------v------+
+-------^-------+ |
| OPTION_VALUES |-------------+
+---------------+
| #product_id |
| #option_id |
| #value_id |
| value_name |
+---------------+
With the Primary, Unique and Foreign Keys:
- PRODUCTS
- PK: product_id
- UK: product_name
- OPTIONS
- PK: product_id, option_id
- UK: product_id, option_name
- OPTION_VALUES
- PK: product_id, option_id, value_id
- UK: product_id, option_id, value_name
- FK: product-id, option_id REFERENCES OPTIONS (product_id, option_id)
- PRODUCT_SKUS
- PK: product_id, sku_id
- UK: sku_id
- FK: product_id REFERENCES PRODUCTS (product_id)
- SKU_VALUES
- PK: product_id, sku_id, option_id
- FK: product_id, sku_id REFERENCES PRODUCT_SKUS (product_id, sku_id)
- FK: product_id, option_id REFERENCES OPTIONS (product_id, option_id)
- FK: product_id, option_id, value_id REFERENCES OPTION_VALUES (product_id, option_id, value_id)
Based on the spreadsheet of how you see your data you could enter data in these tables as follows:
PRODUCTS
========
product_id product_name
---------- ------------
1 Widget 1
2 Widget 2
3 Widget 3
OPTIONS
=======
product_id option_id option_name
---------- --------- -----------
1 1 Size (Widget 1)
1 2 Color (Widget 1)
2 1 Size (Widget 2)
3 1 Class (Widget 3)
3 2 Size (Widget 3)
OPTION_VALUES
=============
product_id option_id value_id value_name
---------- --------- -------- ------------
1 1 1 Small (Widget1; Size)
1 1 2 Large (Widget1; Size)
1 2 1 White (Widget1; Color)
1 2 2 Black (Widget1; Color)
2 1 1 Small (Widget2; Size)
2 1 2 Medium (Widget2; Size)
3 1 1 Amateur (Widget3; Class)
3 1 2 Professional (Widget3; Class)
3 2 1 Medium (Widget3; Size)
3 2 2 Large (Widget3; Size)
PRODUCT_SKUS
============
product_id sku_id sku
---------- ------ ------
1 1 W1SSCW (Widget 1)
1 2 W1SSCB (Widget 1)
1 3 W1SLCW (Widget 1)
1 4 W1SLCB (Widget 1)
2 1 W2SS (Widget 2)
2 2 W2SM (Widget 2)
3 1 W3CASM (Widget 3)
3 2 W3CASL (Widget 3)
3 3 W3CPSM (Widget 3)
3 4 W3CPSL (Widget 3)
SKU_VALUES
==========
product_id sku_id option_id value_id
---------- ------ --------- --------
1 1 1 1 (W1SSCW; Size; Small)
1 1 2 1 (W1SSCW; Color; White)
1 2 1 1 (W1SSCB; Size; Small)
1 2 2 2 (W1SSCB; Color; Black)
1 3 1 2 (W1SLCW; Size; Large)
1 3 2 1 (W1SLCW; Color; White)
1 4 1 2 (W1SLCB; Size; Large)
1 4 2 2 (W1SLCB; Color; Black)
2 1 1 1 (W2SS; Size; Small)
2 2 1 2 (W2SM; Size; Medium)
3 1 1 1 (W3CASM; Class; Amateur)
3 1 2 1 (W3CASM; Size; Medium)
3 2 1 1 (W3CASL; Class; Amateur)
3 2 2 2 (W3CASL; Size; Large)
3 3 1 2 (W3CPSM; Class; Professional)
3 3 2 1 (W3CPSM; Size; Medium)
3 4 1 2 (W3CPSL; Class; Professional)
3 4 2 2 (W3CPSL; Size; Large)