The database schema in a relational database defines tables, attributes (columns), primary and foreign keys, as well as indexes. To create these schema elements in relational databases, you will need a Data Description Language (DDL).
Note
In the code provided at the Packt Publishing website (http://www.packtpub.com/), you will find the complete code to create and query the database.
The queries shown in this chapter are slightly different from the ones provided with the code. In fact, the complete code uses the Apache Derby (a famous embedded SQL database) and, just as most relational databases, has its own dialect. For generality, the SQL code shown in the chapter, is SQL ANSI, which is the standard SQL.
Moreover, the SQL queries in this chapter are written in lowercase to better differentiate them from the Cypher queries. As you know, both SQL and Cypher are case insensitive.
For example, the following CREATE TABLE SQL query creates a table of the reference entries in...