PHP and MySQL Web Development - P47: PHP and MySQL Web Development teaches the reader to develop dynamic, secure, commercial Web sites. Using the same accessible, popular teaching style of the first edition, this best-selling book has been updated to reflect the rapidly changing landscape of MySQL and PHP. | 202 Chapter 8 Creating Your Web Database Next Now that you know how to create users databases and tables you can concentrate on interacting with the database. In the next chapter we ll look at how to put data in the tables how to update and delete it and how to query the database. 9 Working with Your MySQL Database In THIS CHAPTER we ll DISCUSS Structured Query Language SQL and its use in querying ll continue developing the Book-O-Rama database by seeing how to insert delete and update data and how to ask the database questions. Topics we will cover include What is SQL Inserting data into the database Retrieving data from the database Joining tables Updating records from the database Altering tables after creation Deleting records from the database Dropping tables We ll begin by talking about what SQL is and why it s a useful thing to understand. If you haven t set up the Book-O-Rama database you ll need to do that before you can run the SQL queries in this chapter. Instructions for doing this are in Chapter 8 Creating Your Web Database. What Is SQL SQL stands for Structured Query Language. It s the standard language for accessing relational database management systems RDBMS . SQL is used to store and retrieve data to and from a database. It is used in database systems such as MySQL Oracle PostgreSQL Sybase and Microsoft SQL Server among others. 204 Chapter 9 Working with Your MySQL Database There s an ANSI standard for SQL and database systems such as MySQL generally strive to implement this standard. There are some subtle differences between standard SQL and MySQL s SQL. Some of these are planned to become standard in future versions of MySQL and some are deliberate ll point out the more important ones as we go. A complete list of the differences between MySQL s SQL and ANSI SQL at any given version can be found in the MySQL online can find this page at this URL and in many other locations http doc en .