Sams Teach Yourself MySQL in 21 Days, Second Edition

Hands-on: Creating a Simple Function

Now that you have an overview of what needs to be done to create a UDF, let's go step-by-step through the process, with more emphasis on exactly how you will perform such an installation.

You will learn the process using the sample UDFs included in the MySQL distribution. They're in a file called udf-example.cc.

You will

• Compile the C program

• Move it to a place where MySQL can access it

• Tell MySQL to activate its user-defined functions

• Use the functions

• Drop the functions

When you're comfortable with creating UDFs from the examples included, you'll see how to write your own. But first let's go through how to install the sample UDFs.

Compiling the C Program

In this lesson, you will compile the set of sample UDFs ...