What is SQL?

SQL or Structured Query Language is an internatinal standard for manipulating data in a relational database. Each Relational Database system like Oracle, MySQL or SQLite implements its own variation of the standard.

Fortunateley for the types of commands and queries that we will want to write, all of the implementations are much in agreement. The relatively straightforward Select queries we will be writing to access data in our SQLite database will execute un-altered in many of the other environments.

Essentially you only have to learn SQL once.

SQL and Relational database tables

The strength of SQL is that a single SQL statement or query can request data be returned from one or many of the tables in the database. You can essentially define the relationships between tables on-the-fly as part of your query statement.