Database Design of Multi-specification Combinations of Taobao and Jingdong

  mysql, question and Taobao do not have the same practice on multi-specification products

  • regards every combination result as a commodity, so there are many specifications under the same commodity, that is, there are many commodities.

  • Taobao is only a commodity, click on different specifications to show different prices.

The development language is PHP and the database is mysql. Requirements: Merchants can set their own specifications. There is no limit to the number of specifications and specifications.
Which of the following two methods is better? Which is simpler? How should its databases be designed separately?