PHP and MySQL® For Dummies®, 4th Edition

Chapter 13. Ten Things You Might Want to Do Using PHP Functions

In This Chapter

• Finding out about many useful functions

• Understanding what functions can do

One of the strongest aspects of PHP is its many built-in functions. In this chapter, I list the PHP functions that I use most often. Some of them I describe elsewhere in this book, some I mention only in passing, and some I don't mention at all. The PHP language has many hundreds of functions.

Tip

For a complete list of PHP functions, see the PHP documentation at www.php.net/manual/en/funcref.php.

Communicate with MySQL

PHP has many functions designed specifically for interacting with MySQL. I describe the following MySQL functions thoroughly in this book:

mysqli_connect();      mysqli_fetch_assoc()
mysqli_num_rows();     mysqli_query()

The following functions could be useful, but I either don't discuss them or discuss them only briefly:

• mysqli_insert_id($cxn): For use with an AUTO-INCREMENT MySQL column. This function gets the last number inserted into the column.

• mysqli_select_db($cxn,$database): Selects a database. The currently selected database is changed to the specified database. All succeeding queries are executed on the selected database.

• mysqli_fetch_row($result): Gets one row from the temporary results location. The row is put into an array with numbers as keys.

• mysqli_affected_rows($result): Returns the number of rows that were affected by a query — for instance, the number of rows deleted or updated.

• mysqli_num_fields($result): Returns ...