The Internet has allowed consumers and businesses to add another dimension to their purchasing power. The lack of knowledge may make some consumers fearful, while e-commerce is set to revolutionize purchasing for everyone, including the chemical industry. So let's take a look at the inner workings of an e-commerce Web site, from the moment a customer enters the site to the point when an order is processed. A relational database enables this functionality. The tables above contain information that most of us see everyday, but they could be tables in a database.
Tables can have a built-in relationship with other tables, giving the data an added dimension.
For example, let's take the weather table and build a relationship to the U.S. States table. The weather table and the state table both have a column containing the state abbreviation or state code. This relationship can be used to link the two tables. The advantage is that now we can ask the database to return the temperatures from all cities in the state of New York, even if we don't know the abbreviation for New York State. The database will go to the state table, look up New York, work across to the state code column, and grab the state code.