Well, in the eCommerce database, the ProductID should be a numeric value that is set by the database, you should not be setting the ProductID value. the productID column is the primary key column of the database, let the database set the productID value, you can set the ProductSKU column to "CMC-02x03" but that is something completely different.
When working with relational tables, you work with the primary key columns, so if your products record looks like this:
+-----------+------------+-------------+
| ProductID | ProductSKU | ProductName |
+-----------+------------+-------------+
| 1 | CMC-02x03 | Doormat |
+-----------+------------+-------------+
the value that will be used to draw the relations in the productoptions table is the productID.
first you need to define the optiongroup in the options table, for example:
+---------------+------------------+
| OptionGroupID | OptionsGroupName |
+---------------+------------------+
| 1 | size |
+---------------+------------------+
| 2 | color |
+---------------+------------------+
Now, you can define the options that belong to each group in the options table:
+----------+---------------+------------+
| OptionID | OptionGroupID | OptionName |
+----------+---------------+------------+
| 1 | 1 | small |
+----------+---------------+------------+
| 2 | 1 | medium |
+----------+---------------+------------+
| 3 | 1 | large |
+----------+---------------+------------+
| 4 | 2 | red |
+----------+---------------+------------+
| 5 | 2 | yellow |
+----------+---------------+------------+
| 6 | 2 | green |
+----------+---------------+------------+
| 7 | 2 | blue |
+----------+---------------+------------+
now, you can use the productoptions table to relate the product to the options.
using the sample data, the product ID is 1, the optiongroupid for the color option group is 2 and the option ID for the red yeelow blue colors are 4, 5, and 7
we need to following records to create a red yellow and blue option for our sample product:
+-----------------+-----------+----------+---------------+----------------------+
| ProductOptionID | ProductID | OptionID | OptionGroupID | OptionPriceIncrement |
+-----------------+-----------+----------+---------------+----------------------+
| 1 | 1 | 4 | 2 | |
+-----------------+-----------+----------+---------------+----------------------+
| 2 | 1 | 5 | 2 | |
+-----------------+-----------+----------+---------------+----------------------+
| 3 | 1 | 7 | 2 | |
+-----------------+-----------+----------+---------------+----------------------+