Sams Teach Yourself SQL in 21 Days, Fourth Edition

An Overview of SQL

SQL is the de facto standard language used to manipulate and retrieve data from these relational databases. Through SQL, a programmer or database administrator can do the following:

• Modify a database's structure
• Change system security settings
• Add user permissions to databases or tables
• Query a database for information
• Update the contents of a database

Note

The term SQL can be confusing. The S, for Structured, and the L, for Language, are straightforward enough, but the Q is a little misleading. Q, of course, stands for Query, which—if taken literally—would restrict you to asking the database questions. But SQL does much more than ask questions. With SQL you can also create tables, add data, delete data, splice data together, trigger ...