SQL (Structured Query Language) is an industry standard language used to interact with relational databases. In practice, SQL statements are seldom written “by hand” since there are so many high-quality visual SQL tools available (e.g. the Microsoft Access query builder). These tools provide for visual definition of database operations with the resulting SQL statement(s) then be copied and pasted into other applications. Nevertheless, in order to use these visual tools effectively the learner needs to understand the basics of SQL covered in this module.